R1:ecfb72071372

Adding some filters and queries to Macro application

Summary:
Fixes T2778

Introduces `PhabricatorMacroQuery`, which should consolidate all queries regarding macros

Adds `PolicyInterface` to `PhabricatorImageMacro`, as else the query would fail (we should consider adding it to the ApplicationTransaction instead, if that was ever planned)

Adds `Active Macros` filter, making it the default

Adds `My Macros` filter. You may ask why it overwrites `$authors`. Well, I did not want the page jump to the…