- fix geckodriver version used following `backend-dev-e2e` base image update
- use Prosody image `prosodyim/prosody:0.12` instead of a deprecated one
- update `pubsub` image with base image update and use of new repos names
- Use the new `wait_for_service` option to be sure that Prosody is launched.
- Use the new `init_script_path` option to initiate forums and bookmark a demo room.
- Activate MUC service.
- Change log formats to make them more readable.
Due to mod_privilege and PAM implementation in Libervia Pubsub, permissions have been
udpated in `prosody.cfg.lua`, with the new `iq` permission and namespace delegation needed
for PAM.
`"urn:xmpp:delegation:2:bare:disco#info:*"` namespace delegation was also missing.
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