Embed build-time nvjitlink version and make accessible

[vyasr]

pynvjitlink should embed the CUDA version used at build-time as a compile-time constant accessible via a Python API. That would be very helpful for us for debugging in the future. Since we're statically linking our only recourse for debugging purposes right now is to check when a particular pynvjitlink package was built and then see what version of CUDA the build scripts used at that time.

Once we provide this constant, we could also automatically check at import-time whether the CUDA runtime/driver on the system could lead to version mismatches that are unsupported by the current version of pynvjitlink.

Originally posted by @vyasr in #33 (comment)

[jakirkham]

Would also recommend we do a version check during import pynvjitlink and error informatively if we find a mismatch

[gmarkall]

Perhaps we should do this by exposing nvJitLinkVersion() rather than adding our own logic to capture the build-time version.