Request: Add "avatarDidLoad"

[Boumety]

Add "avatarDidLoad" with a function as a callback.

This could be useful for games that change the wearables of the Player.

[gdevillele]

Note : this is in the contexte of ui_avatar module, get function

[aduermael]

We also need to override/cancel ongoing requests when setting wearables. It shouldn't be necessary to wait for requests to end to update avatar parts. This avatarDidLoad callback would still be useful either way.

[aduermael]

I believe this issue is outdated. It's now possible to change avatar wearables, naturally overriding / cancelling ongoing requests.