chore: removal of session and session-request observer

[BenedictHomuth]

Description

Removed the session and session request observer and moved the corresponding logic into the service layer.

Two more changes:

1. Created one new db function, since before this logic was written plainly in the observer.

2. Since user updates need to be published to all board members (e.g. on name or appearance change) I added the realtime package to the UserService. Before it was implicitly handled in one of the observers.

Changelog

• removed session and session observer
• moved logic into corresponding service layers
• Created a new db function which fetches all currently connected sessions of a given user
• Added the realtime package to the UserService

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• The light- and dark-theme are both supported and tested
• The design was implemented and is responsive for all devices and screen sizes
• The application was tested in the most commonly used browsers (e.g. Chrome, Firefox, Safari)

(Optional) Visual Changes

[octomind-dev]

🐙 Octomind

Test Report: 0/14 successful.

description	status	details
About Section Visibility Test	Failed ❌	click
change avatar	Failed ❌	click
check Privacy Policy	Failed ❌	click
check terms & conditions	Failed ❌	click
close cookie banner - front page	Failed ❌	click
close cookie banner - sign-in	Failed ❌	click
create and delete board columns	Failed ❌	click
create_and_delete_notes_and_actions_v2	Failed ❌	click
create lean coffee board	Failed ❌	click
edit_notes_and_actions_v5	Failed ❌	click
get started	Failed ❌	click
share_session	Failed ❌	click
sign-in	Failed ❌	click
test all ways to open the setup flow	Failed ❌	click

commit sha: 3b7dc2b

[github-actions]

The deployment to the dev cluster was successful. You can find the deployment here: https://4203.development.scrumlr.fra.ics.inovex.io
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To redeploy rerun the workflow.
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Deployed Images

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• ghcr.io/inovex/scrumlr.io/scrumlr-server:sha-ec5026c

[octomind-dev]

🐙 Octomind

Test Report: 12/14 successful.

description	status	details
About Section Visibility Test	Passed ✅	click
change avatar	Failed ❌	click
check Privacy Policy	Passed ✅	click
check terms & conditions	Passed ✅	click
close cookie banner - front page	Passed ✅	click
close cookie banner - sign-in	Passed ✅	click
create and delete board columns	Failed ❌	click
create_and_delete_notes_and_actions_v2	Passed ✅	click
create lean coffee board	Passed ✅	click
edit_notes_and_actions_v5	Passed ✅	click
get started	Passed ✅	click
share_session	Passed ✅	click
sign-in	Passed ✅	click
test all ways to open the setup flow	Passed ✅	click

commit sha: ec5026c

[mateo-ivc]

lgtm 👍🏽