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.

That is the option to make SQLite reject misuses of double quotes instead
of single quotes. Most SQLite builds are forgiving, but some forks proposing
a CMake build system default to SQLITE_DQS=0

This is aimed at detecting running a PROJ version against a proj.db that is not
meant to work with it. This happens sometimes in complex setups mixing PROJ
versions. Hopefully this will help spotting the issue earlier.