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, 20 insertions, 7 deletions

diff --git a/ports/field3d/CONTROL b/ports/field3d/CONTROL
deleted file mode 100644
index d16bd4cb4..000000000
--- a/ports/field3d/CONTROL
+++ /dev/null
@@ -1,7 +0,0 @@
-Source: field3d
-Version: 1.7.3
-Port-Version: 1
-Homepage: https://github.com/imageworks/Field3D
-Description: An open source library for storing voxel data. It provides C++ classes that handle in-memory storage and a file format based on HDF5 that allows the C++ objects to be written to and read from disk.
-Build-Depends: hdf5, boost-regex, boost-thread, boost-program-options, boost-system, openexr, boost-foreach, boost-test, boost-timer, boost-format
-Supports: !(uwp)
diff --git a/ports/field3d/vcpkg.json b/ports/field3d/vcpkg.json
new file mode 100644
index 000000000..21ca20bdc
--- /dev/null
+++ b/ports/field3d/vcpkg.json
@@ -0,0 +1,20 @@
+{
+  "name": "field3d",
+  "version-string": "1.7.3",
+  "port-version": 2,
+  "description": "An open source library for storing voxel data. It provides C++ classes that handle in-memory storage and a file format based on HDF5 that allows the C++ objects to be written to and read from disk.",
+  "homepage": "https://github.com/imageworks/Field3D",
+  "supports": "!uwp",
+  "dependencies": [
+    "boost-foreach",
+    "boost-format",
+    "boost-program-options",
+    "boost-regex",
+    "boost-system",
+    "boost-test",
+    "boost-thread",
+    "boost-timer",
+    "hdf5",
+    "openexr"
+  ]
+}