pgsql: Honor MSVC WindowsSDKVersion if set

Honor MSVC WindowsSDKVersion if set

Add a line to the project file setting the target SDK. Otherwise, in for
example VS2017, if the default but optional 8.1 SDK is not installed the
build will fail.

Patch from Peifeng Qiu, slightly edited by me.

Discussion: /messages/by-id/CABmtVJhw1boP_bd4=b3Qv5YnqEdL696NtHFi2ruiyQ6mFHkeQQ@mail.gmail.com

Backpatch to all live branches.

Branch
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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/165f4eecfeb71581c05f371f72eb99742cbae18c

Modified Files
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src/tools/msvc/MSBuildProject.pm | 13 +++++++++++++
1 file changed, 13 insertions(+)