Enable setting a maximum number of hero abilities

[DimasDSF]

Currently every hero has 24 ability slots, any attempt to add more abilities (hidden or visible) results in a failure.

For example Invoker already has 24 abilities(qwe+abilities+invoker_empty1 + invoker_empty2(empty icons with tooltips)+8 talents)

[Perryvw]

I don't see why you would ever have to give a hero more than 16 abilities at one time. You can dynamically add/remove abilities too instead of hiding them.

[DimasDSF]

Invoker in "base game" already has all 24 ability slots fillled and some functions require abilities to be passed to them or they fill console with errors
like docleaveattack does on every hit if the hAbility is nil
CDOTA_AttackRecordManager::GetRecordByIndex - Could not find attack record (0)!.
also reflecting a spell in a similar way to lotus orb with a lua modifier or ability requires that the reflecting hero has a free slot to store the ability being cast, so if I dont want to change basedota heroes and just add consumable items that grant those abilities I am stuck.
And if any update in the future adds more talents or a couple more "generic_hidden" abilities to every hero it will reduce the number of free ability slots even more.
While solving this problem could be as simple as setting a gamerule if it was possible.