Change redirect behaviour if you navigate to a forbidden page

[Elblinator]

Current behavior
If you try to navigate to a page which you are not allowed to see, then you are directly redirected to the "You are not supposed to be here" page.

Wanted behavior
If you try to navigate to a page which you are not supposed to see then you should be automatically directed to the dashboard.
One exception:
If a user is only allowed to see one single meeting then the user should be redirected to the dashboard and then to this meeting. The redirect from the dashboard to the single meeting is already implemented, you just have to make sure that it still works afterwards.

[luisa-beerboom]

So am I understanding correctly that if, for example, admins decide to put a link to a particular motion/election/topic into f.E. the meeting start page text field, users, that don't have the right to see said page, should just be thrown to the dashboard without any explanation of why this happened whatsoever?
Wouldn't that appear a bit buggy?

Also I was wondering about what the problem with the current functionality actually was

[Elblinator]

Wouldn't that appear a bit buggy?

The admins shouldn't link a page that the participants are not allowed to see. It may indeed be a bit confusing for the participants to be directed to the dashboard.
We definitely want the participants to be directed to the dashobard.
We could also opena pop-up dialog with "sth sth, you are trying to see a page you're not suppossed to, you will be redirected." and the window could have a timer and a "reload" button. If the reload button is pressed then you are redirected or if the timer runs out then you are also redirected.
That would be explaining the behaviour but still force you to be navigated to the dashobard. (This behaviour is also possible just that the pop-up opens but you are directly directed to the dashboard.

Also I was wondering about what the problem with the current functionality actually was

The problem came from switching a user who is locked out of a meeting (#4235).
Situation: When you were in a meeting and you were looked out then the display of this meeting was buggy (menu on the left, the autopilot, etc.).
There were several moment where the client could not detect whether or not you were trying navigate to a forbidden page purposefully or accidentially, and if you were there accidentially you got stuck on pages. To prevent this all together we decided to just throw users to biggest access point they could have (the dashboard