[gdal-dev] cmake status update - 99% good news!

[Kai Pastor, DG0YT]

I made an initial attempt on gdal with cmake for vcpkg: 
https://github.com/microsoft/vcpkg/pull/22392

Now vcpkg's default is static linkage on Linux and macOS. AFAICT static 
linkage is not covered very well. Fixing this needs a lot of work either 
on the find modules, or on getting dependencies to provide exported 
config. In some cases (e.g. GEOS), config files already exist, but they 
are neither used nor a drop-in replacement (target names differ).

On the export side, all custom find modules must be made available to 
the exported configuration if not burning the depended-on libraries into 
the exported cmake config. Generating a complete gdal.pc needs work, 
too. CMake doesn't provide any help ATM. (But note 
https://gitlab.kitware.com/cmake/cmake/-/issues/22621.)

This is not meant as an argument against shortening the release schedule 
for cmake. I just want to underline that the CMake build system will 
continue to need significant changes, including user-facing changes.

Kai Pastor