package_rpm.bbclass: Replace shell provides/requires script with python version

package_rpm.bbclass: Replace shell provides/requires script with python version

The existing shell script is a fork bomb and forks off hundreds of
grep/cur/wc calls as it reads from its input stream and iterates over
the file data table for each line of input. This patch replaces the
shell code with python code which doesn't exec anything and hence runs
much faster without the exec() overhead. This speeds up rpm packaging
considerably, as can be measured simply by timing it, or watching the
processor utilisation.

(From OE-Core rev: 2fb5f72b47840ed7f540df181595878e3f5ba4c6)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>