Supply the FIPS build settings for Windows - #468

configure sets a group of macros on Linux that a Windows FIPS build silently
omits. Nothing fails at build time; the results are malformed PKCS#8, RSA-PSS
interop failures against OpenSSL, and a struct sp_int layout mismatch.
Ship them as IDE/WINVS/user_settings-fips.h, included at the end of the bundle's
IDE/WIN10/user_settings.h so wolfSSL and wolfProvider compile against the same
one. WOLFSSL_SP_INT_NEGATIVE is ABI-affecting, so the two builds disagreeing on
it is silent and fatal.
The README gains the FIPS procedure: enabling FIPS in the bundle, the v143
retarget, naming the .vcxproj rather than the .sln MSBuild 17 cannot load,
building the test app that reports the in-core hash, and the overrides the unit
tests need. It also records that DLL Release|x64 and DLL Debug|x64 are the
approved FIPS configurations and that their project settings are correct as
shipped.
No source or project files change.