* Fix joined hierarchical filtering
* Fix scene performer tag filter
* Generalise performer tag handler
* Add unit tests
* Add equals handling
* Make performer tags equals/not equals unsupported
* Make tags not equals unsupported
* Make not equals unsupported for performers criterion
* Support equals/not equals for studio criterion
* Fix marker scene tags equals filter
* Fix scene performer tag filter
* Make equals/not equals unsupported for hierarchical criterion
* Use existing studio handler in movie
* Hide unsupported tag modifier options
* Use existing performer tags logic where possible
* Restore old parent/child filter logic
* Disable sub-tags in equals modifier for tags criterion