[BE1] process meeting messages and include unprocessed messages in rumor state answer

[emonnin-epfl]

Rumors of rumors state that answer messages now also contain unprocessed messages. Meeting-related messages are now stored and processed.

[github-actions[bot]]

Pull reviewers stats

Stats of the last 30 days for popstellar:		User	Total reviews	Time to review	Total comments
	K1li4nL 🥇	23 ▀▀▀▀	2d 10h 24m)) ▀	14 ▀▀
	arnauds5 🥈	7 ▀	4h 29m))	4 ▀
	matteosz 🥉	7 ▀	3d 16h 5m)) ▀	21 ▀▀▀
	emonnin-epfl	5 ▀	8h 20m))	8 ▀
	onsriahi14	3 ▀	1d 10h 51m))	4 ▀
	quadcopterman	3 ▀	10d 7h 3m)) ▀▀▀	1
	1florentin	2	10d 5h 50m)) ▀▀▀	0
	sgueissa	2	12h 56m))	5 ▀
	MariemBaccari	2	22h 39m))	6 ▀
	simone-kalbermatter	2	5h 32m))	0
	Kaz-ookid	1	3d 19h 13m)) ▀	5 ▀

^{⚡️ Pull request stats}

[sonarcloud[bot]]

Quality Gate passed for 'PoP - PoPCHA-Web-Client'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud[bot]]

Quality Gate passed for 'PoP - Be2-Scala'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud[bot]]

Quality Gate passed for 'PoP - Be1-Go'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
67.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud[bot]]

Quality Gate passed for 'PoP - Fe2-Android'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud