AW: VS2022: Support Visual Studio 2022 on Windows

Hello Daniel,

Thank you for looking into it.

My skills with git are minmal yet and I am working on a correct development platform, so sorry for any inconveniances
frommy side . 

When upgraded Microsoft jumped directly from Preview 7 to Preview 7.1 of VS2022 by skipping the release version of 7.0.

I had to install it on a different machine to test it with the final VS2022 version from november 8.

On both platforms the build of snapshot from 19.11.2021 is successfull but gives the following  warnings which seem not
correlatedto the proposed patch: 

Der Buildvorgang wurde erfolgreich ausgeführt.

"C:\pgdev\postgresql-15devel\pgsql.sln" (Standardziel) (1) ->
"C:\pgdev\postgresql-15devel\postgres.vcxproj" (Standardziel) (2) ->
(ClCompile Ziel) ->
  C:\pgdev\postgresql-15devel\src\backend\access\heap\pruneheap.c(858,18): warning C4101: "htup": Unreferenzierte
lokaleVariable [C:\pgdev\postgresql-15devel\postgres.vcxproj] 
  C:\pgdev\postgresql-15devel\src\backend\access\heap\pruneheap.c(870,11): warning C4101: "tolp": Unreferenzierte
lokaleVariable [C:\pgdev\postgresql-15devel\postgres.vcxproj] 

    2 Warnung(en)
    0 Fehler

(Meaning 2 unreferenced local variables in pruneheap.c)

The build produced .vcxproj files with ToolsVersion="17.0", so it recognized the new environment correctly.

I corrected some ommissions in _GetVisualStudioVersion in VSObjectFactory.pm.

Please find attached the corrected patch version v4.

Due to my restricted devlopment environment I appreciate if anybody can test the resulting binaries (but MS seems not
havechanged much on the C Build environment internally). 

Thanks

Hans Buschmann