Simple rooms get & UI

[JonasWanke]

Closes: #303

Connection to Matrix works and rooms are listed. This also fixes our recurring problem of Hive reporting an unknown adapter ID by simply registering all adapters before they are used.

The CI problem is a known issue (simolus3/moor#581) that has to be fixed before the messenger itself can be merged, though we can already merge this branch onto feature/messenger despite the build failure.

[github-actions[bot]]

:warning: Unicorn Report

:warning: 4 Warnings

• Merge pull request #315 from schul-cloud/build/simplify-analysis-options Enforce stricter linter rules
• Merge branch 'master' into refactor/migrate-assignment-module
• Merge pull request #301 from schul-cloud/refactor/migrate-assignment-module Migrate assignment module
• Merge branch 'master' into issue/303-simple-messages-get-ui

:information_source: 1 Info

• This PR will close the following issues: #303

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[github-actions[bot]]

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