Hide empty tabs (and the tab strip, if all are).

[RokeJulianLockhart]

Your use case

What would you like to do?

The "Chat" and "Rooms" tabs should dynamically appear and disappear depending upon whether any constituents exist. Additionally, if – consequently – solely one tab is existent, all of the tabs should disappear, because the header that is within the title-bar is adequate:

This is additionally true for the small header that is above the list of rooms:

Why would you like to do it?

They waste display real estate when empty.

How would you like to achieve it?

Aforexplained.

Have you considered any alternatives?

No.

[RokeJulianLockhart]

#4764 (comment)

It's worth considering whether these should be instead transferred to https://github.com/element-hq/element-meta/issues/new?assignees=&labels=T-Enhancement&projects=&template=enhancement.yml.