Move modifiers into selectable options in object filter selectors

[WithoutPants]

Removes the modifier buttons from the Performer, Studio and Tags criterion editors in favour of selectable items that are (imo) more intuitive and use more user-friendly language:

Any and None are the equivalent of not null and is null respectively, and only show if nothing else is selected. If either of these are selected, then no other options are shown:

If one or more objects are selected, the Any of and Only options are made available. Any of is the equivalent of includes (instead of includes all), and only is the equivalent of equals.

These special items are shown in parentheses, italics and with a lower opacity to distinguish them from regular items.

Given that it's a single value field, the studio selector does not have the Any of or Only options.