#934472 reportbug/utils.py: fix versioned provides recognition

get_package_info() so far did not support parsing package 'Provides:' metadata lines where any version is specified. Fix this by recognizing version restriction both for the package(s) we are looking for and the packages that we are not interested in.

Since the recognized provides now may contain such a version restriction and we really only want the package name, remove the unneeded information before returning.