Add PG17 meson build support

[muralikrishna05]

The PostgreSQL 17 on Windows supports only Meson build system, where the build and source directories are separate. Therefore, some of the header files required are present in the source directory and some in the build directory.

Add a new variable PGBUILDPATH to define the build directory. Also, add a separate PropertyGroup to define the postgres.lib file path, as this file generated location is different in PG 17 compare with back branches.

Required build parameters are passed to msbuild, so updating settings.projinc is avoided.

Successfully test build the changes against PG17 and PG16 builds.

[muralikrishna05]

This is fine for now, but long-term we need to figure out how this should be built 'correctly' under Meson.

@dpage I didn't understand this "long-term we need to figure out how this should be built 'correctly' under Meson".

[dpage]

This is fine for now, but long-term we need to figure out how this should be built 'correctly' under Meson.

@dpage I didn't understand this "long-term we need to figure out how this should be built 'correctly' under Meson".

Well the point of Meson in PostgreSQL is to get rid of MSVC++ project files from the source tree. In the future, we need to figure out how to do the same here.

[muralikrishna05]

This is fine for now, but long-term we need to figure out how this should be built 'correctly' under Meson.

@dpage I didn't understand this "long-term we need to figure out how this should be built 'correctly' under Meson".

Well the point of Meson in PostgreSQL is to get rid of MSVC++ project files from the source tree. In the future, we need to figure out how to do the same here.

Right, Got it. Thank you Dave. Can you pls merge this pull request to master branch.