[engine] add [filter_ability] in filter to filter abilities on criteria other than type or identifier.

[newfrenchy83]

Although as a general rule the use of ability_id/type(_active) is sufficient to define an event or to remove the ability in question in [object] (and again, taking the tag into account is illusory, only the 'id really counts), it may be that extensions contain many abilities of the same type and that filtering some of them with common characteristics (affect_self/allies/enemies, value/add/multiply) could be more interesting than listing the ids of each ability, especially if the list is long.

If extension developers are interested in the concept, I invite them to look at https://github.com/wesnoth/wesnoth/pull/7168 for details and let me know on this thread if it's worth it or No.

[Toranks]

If the idea is to extend the ability filtering in general, taking into account more parameters than just the id, I'm interested. Not just for remove_ability, but anywhere with StandardUnitFilter

[newfrenchy83]

this is the idea, remove_ability, event(and lua?) and also use overwrite_specials attribute more select inabilities used like weapon.