cmake: add native `pkg-config` detection for mbedTLS, MSH3, Quiche, Rustls, wolfSSL

Also:
- detect and add required system libraries for Rustls on macOS and
  non-Windows.
- add Linux CMake jobs for the touched dependencies.
  Caveats:
  - MSH3 generates a broken `libmsh3.pc`, so needs manual config.
    Upstream PR: https://github.com/nibanks/msh3/pull/225
  - Rustls `.pc` file missing, so needs manual config.

An internal change worthy of mention is that we are using the lib path
and name information returned by `pkg-config` as-is. Meaning the libname
doesn't include the full path, like it's usual with native cmake
detection. The path comes separately and needs to be rolled separately.
For this we add it to targets via `link_directories()`. We also keep tab
of them in `CURL_LIBDIRS` and use that in `libcurl.pc`. Feature checks
also need to receive these paths. CMake doesn't offer
a `CMAKE_REQUIRED_*` variable for this purpose, only
a `CMAKE_REQUIRED_LINK_OPTIONS` accepting raw linker flags. Add a macro
to convert a list of paths to linker options to solve it. wolfSSL
requires this for now.

Closes #15193