fixes https://github.com/TryGhost/Team/issues/2112
- Removed a bit of duplicate code across templates and components that was used to handle filters
- Updated filter objects to contain information about the filter
- Added resource filters that are able to select a single resource, which can be used in columns
- Filters can now define columns by themselves. Not all columns already make use of this functionality, but we can move those over later (cleanup: https://github.com/TryGhost/Team/issues/2133)
- The filter definitions became quite long. We should move them to separate files in the future: https://github.com/TryGhost/Team/issues/2134
- Filters can now have custom NQL parsing
- Improved support for parsing recursive or grouped NQL queries
- Added support for filtering members by feedback