Allow to add new identities to be included in disco#info replies

Description

Create new interfaces ServerIdentitiesProvider and UserIdentitiesProvider to be used by IQDiscoInfoHandler as a way to dynamically add new identities to be included in disco#info responses. These new interfaces are expected to be implemented by server modules.

This new feature was implemented by Armando as part of the GSoC project.

Environment

None
Fixed

Assignee

Gaston Dombiak

Reporter

Gaston Dombiak