Bulk convert control files. (#19986)

```
function Convert-Control {
    Param($full)
    .\vcpkg.exe format-manifest $full
    $root = $full.Substring(0, $full.Length - 7) # CONTROL
    $new = $root + 'vcpkg.json'
    $content = Get-Content -Raw $new
    $asJson = ConvertFrom-Json $content -AsHashtable -Depth 100
    $oldVersion = $asJson['port-version']
    if ($null -eq $oldVersion) {
        $oldVersionFull = $asJson['version-string']
        Write-Host "Got version $oldVersionFull"
        $match = [System.Text.RegularExpressions.Regex]::Match($oldVersionFull, '^(.+)-(\d+)$')
        if ($match.Success -and -not [System.Text.RegularExpressions.Regex]::IsMatch($oldVersionFull, '^\d\d\d\d-\d\d-\d\d$')) {
            $newFullVersion = [string]$match.Groups[1].Value
            $oldVersion = [int]$match.Groups[2].Value
            Write-Host "newFullVersion $newFullVersion oldVersion $oldVersion"
            $newVersion = $oldVersion + 1
            $asJson['version-string'] = $newFullVersion
            Write-Host "Previous version for $full extracted from version field -- setting version-string $newFullVersion and port-version $newVersion"
        } else {
            Write-Host "No previous version for $full -- setting 1"
            $newVersion = 1
        }
    } else {
        $newVersion = [int]$oldVersion + 1
        Write-Host "New version for $full : $newVersion"
    }

    $asJson['port-version'] = $newVersion

    $content = ConvertTo-Json $asJson -Depth 100
    Set-Content -Path $new -Value $content
    .\vcpkg.exe format-manifest $new
}

Get-ChildItem ports\CONTROL -Recurse | Foreach-Object {
    Convert-Control $_.FullName
}

git commit -am "this message"
.\vcpkg.exe x-add-version -all
git commit -a --amend
```

2 files changed, 124 insertions, 28 deletions

diff --git a/ports/osg/CONTROL b/ports/osg/CONTROL
deleted file mode 100644
index a05f5abe7..000000000
--- a/ports/osg/CONTROL
+++ /dev/null
@@ -1,28 +0,0 @@
-Source: osg
-Version: 3.6.5
-Port-Version: 7
-Homepage: https://github.com/openscenegraph/OpenSceneGraph
-Description:  The OpenSceneGraph is an open source high performance 3D graphics toolkit.
-Build-Depends: zlib, fontconfig (!windows), expat (windows), openimageio (osx)
-
-Feature: collada
-Description: Support for Collada (.dae) files
-Build-Depends: collada-dom
-
-Feature: tools
-Description: Enable to build OSG Applications (e.g. osgviewer)
-Build-Depends: freetype, sdl1, curl, libjpeg-turbo, libpng, libiconv (windows)
-
-Feature: examples
-Description: Enable to build OSG Examples
-Build-Depends: freetype, sdl1, sdl2, libiconv (windows)
-
-Feature: plugins
-Description: Build OSG Plugins - Disable for compile testing examples on a time limit
-Build-Depends: freetype, sdl1, curl, openexr, ilmbase, gdal, giflib (windows), jasper, libjpeg-turbo, libpng, tiff, libxml2 (windows), libiconv (windows), libgta, liblas, nvtt (!x86), coin, boost-asio (!windows), boost-core (!windows), boost-logic (!windows), boost-lexical-cast (!windows), boost-smart-ptr (!windows), boost-tuple (!windows), boost-bind (!windows)
-
-Feature: packages
-Description: Set to ON to generate CPack configuration files and packaging targets
-
-Feature: docs
-Description: Build OpenSceneGraph reference documentation using doxygen (use: make doc_openscenegraph doc_openthreads
diff --git a/ports/osg/vcpkg.json b/ports/osg/vcpkg.json
new file mode 100644
index 000000000..8ad7f03b1
--- /dev/null
+++ b/ports/osg/vcpkg.json
@@ -0,0 +1,124 @@
+{
+  "name": "osg",
+  "version-string": "3.6.5",
+  "port-version": 8,
+  "description": "The OpenSceneGraph is an open source high performance 3D graphics toolkit.",
+  "homepage": "https://github.com/openscenegraph/OpenSceneGraph",
+  "dependencies": [
+    {
+      "name": "expat",
+      "platform": "windows"
+    },
+    {
+      "name": "fontconfig",
+      "platform": "!windows"
+    },
+    {
+      "name": "openimageio",
+      "platform": "osx"
+    },
+    "zlib"
+  ],
+  "features": {
+    "collada": {
+      "description": "Support for Collada (.dae) files",
+      "dependencies": [
+        "collada-dom"
+      ]
+    },
+    "docs": {
+      "description": "Build OpenSceneGraph reference documentation using doxygen (use: make doc_openscenegraph doc_openthreads"
+    },
+    "examples": {
+      "description": "Enable to build OSG Examples",
+      "dependencies": [
+        "freetype",
+        {
+          "name": "libiconv",
+          "platform": "windows"
+        },
+        "sdl1",
+        "sdl2"
+      ]
+    },
+    "packages": {
+      "description": "Set to ON to generate CPack configuration files and packaging targets"
+    },
+    "plugins": {
+      "description": "Build OSG Plugins - Disable for compile testing examples on a time limit",
+      "dependencies": [
+        {
+          "name": "boost-asio",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-bind",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-core",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-lexical-cast",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-logic",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-smart-ptr",
+          "platform": "!windows"
+        },
+        {
+          "name": "boost-tuple",
+          "platform": "!windows"
+        },
+        "coin",
+        "curl",
+        "freetype",
+        "gdal",
+        {
+          "name": "giflib",
+          "platform": "windows"
+        },
+        "ilmbase",
+        "jasper",
+        "libgta",
+        {
+          "name": "libiconv",
+          "platform": "windows"
+        },
+        "libjpeg-turbo",
+        "liblas",
+        "libpng",
+        {
+          "name": "libxml2",
+          "platform": "windows"
+        },
+        {
+          "name": "nvtt",
+          "platform": "!x86"
+        },
+        "openexr",
+        "sdl1",
+        "tiff"
+      ]
+    },
+    "tools": {
+      "description": "Enable to build OSG Applications (e.g. osgviewer)",
+      "dependencies": [
+        "curl",
+        "freetype",
+        {
+          "name": "libiconv",
+          "platform": "windows"
+        },
+        "libjpeg-turbo",
+        "libpng",
+        "sdl1"
+      ]
+    }
+  }
+}