Can't set username for xf:avatar

[Kirby]

Affected version

2.2.13

Template tag xf:username accepts attribute username which allows to override the username but template tag xf:avatar does not process this attribute.

So if a username is override for the user link and a dynamic avatar is rendered, the latter is taken from the the username in user entity causing an inconsistent display (Overriden username in user link + letter from original username)