Allow to collapse some elements such as big code block

[Porkepix]

Describe the problem

Sometimes someone or a bot might post some big blocks such as block code, or quote a particularly long issue, which might take your whole screen and even more.

Describe the solution you'd like

It would come handy to be able to have this collapsed (as done in Element, for example)

Alternatives considered

None

Additional context

No response

[N-R-K]

Was about to open an issue for the same thing but then noticed this one.

Another similar issue: https://github.com/cinnyapp/cinny/issues/371