Fixed LIBM target issue and added the missing file gettimeoftheday c

[Mahesh1998]

1. MSVC cmake doesn't find conda libraries with prefix. So, we use conda cmake.
2. MSVC cmake requires lot of changes to detect conda libraries. But conda cmake detected all conda libraries without any changes.
3. The 2 changes are from the error message LIBM target and the missing gettimeoftheday c file. So, I copied the file from postgresql by following the commit message (add gettimeofday windowss implemenation from postgresql).
4. Conda cmake uses the same target as MSVC cmake (Visual Studio 17 2022).

How to build: msbuild GRASS.sln

Currently Fixing MSVC errors