This adds the NKG 2008 and 2020 transformations to proj.db. The NKG
transformations offers transformations between global reference frames
and the national realisations of ETRS89 in Denmark, Estonia, Finland,
Latvia, Lithuania, Norway and Sweden.

The 2008 transformations are already implemented in the NKG 2008 file
but will now be more accessible with the modern API.

The 2020 transformations are new to PROJ and offers and updated version
of the 2008 transformations using a new and improved deformation model
(eu_nkg_nkgrf17vel.tif). A 2020 version of the NKG transformations are
currently not available for Norway but will in all likelyhood be
included at a later point in time.

as CompoundCRS with a VerticalCRS being an ellipsoidal height, which is
not conformant. But needed for LAS 1.4 that only supports WKT1

This is a partial backport of https://github.com/OSGeo/PROJ/pull/2450,
with only the new ALLOW_ELLIPSOIDAL_HEIGHT_AS_VERTICAL_CRS=YES option
of proj_as_wkt()

Corrected formula given by @evanmiller

Currently the output of the cct utility is different between radians
and degrees (as expected by cct), because of a bug in cct:

$ printf "1 2\n" | cct -z 0 -t 0 +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=rad
  1.0000000000    2.0000000000        0.0000        0.0000

$ printf "1 2\n" | cct -z 0 -t 0 +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=deg
       1.0000         2.0000        0.0000        0.0000

The arguments to the printf format string are as follows:

 * radians: width 14, precision 10
 * degrees: width 13, precision  4 (this is by mistake. bug!)

After the suggested fix has been applied, output will be the same for
both radians and degrees:

$ printf "1 2\n" | cct -z 0 -t 0 +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=rad
  1.0000000000    2.0000000000        0.0000        0.0000

$ printf "1 2\n" | cct -z 0 -t 0 +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=deg
  1.0000000000    2.0000000000        0.0000        0.0000

The cause of the bug is that cct does test if it "has radians to output",
but "neglects" to test if it "has degrees to output", resulting in using
different arguments to the printf format string in the latter case.

The fix makes cct test if it "has either radians or degrees to output".