654501: add some filtering to list available
add completion for new CLI filters
remove unused args, remove unnecessary idcert read
fix wrong index in get_filtered_pools_list
Add some tests cases for managerlib.get_avail_ents

managerlib.get_available_entitlements that is.
removed subscribed filter, added testing
stylish cleanups
Add 'providedProducts' to test pool

For managercli ListCommand tests.
Use all keywords args for call to get_avail_ents

Lots of args here, mostly optional, easier to follow
if all specify their keyword.
Merge pull request #773 from candlepin/ckozak/match_gui_filters

654501: add some filtering to list available