fixes #1804 - find hosts through nested hostgroups on puppet class search
refs #2189 - update host group parameter search tests
Fixes #4927 - Extend foreman-debug to look for extensions provided by plugins.

This assumes a directory called /usr/share/foreman/script/foreman-debug.d.
Any *.sh file in there is sourced. The expectation is that plugins would put
files into this locations and can add files or commands as necessary
fixes #4800 SLES special handling in facts parser