curl.rc: embed manifest for correct Windows version detection

* enable it in `src/Makefile.m32`
* enable it in `winbuild/MakefileBuild.vc` if a custom manifest is
  _not_ enabled via the existing `EMBED_MANIFEST` option
* enable it for all Windows CMake builds (also disable the built-in
  minimal manifest, added by CMake by default.)

For other build systems, add the `-DCURL_EMBED_MANIFEST` option to
the list of RC (Resource Compiler) flags to enable the manifest
included in `src/curl.rc`. This may require to disable whatever
automatic or other means in which way another manifest is added to
`curl.exe`.

Notice that Borland C doesn't support this method due to a
long-pending resource compiler bug. Watcom C may also not handle
it correctly when the `-zm` `wrc` option is used (this option may
be unnecessary though) and regardless of options in certain earlier
revisions of the 2.0 beta version.

Closes https://github.com/curl/curl/pull/1221
Fixes https://github.com/curl/curl/issues/2591