Header navigation configuration to avoid content clipping
## What
Depending on the breakpoint and language settings, content in the main header can be clipped or altogether not visible.
**Examples**



## Proposal
* Audit current navigation configurations and breakpoint changes.
* Concept configuration and/or overflow solutions that are:
- Language and font size agnostic
- Anchored on *content* and not breakpoints
- Accessible
/cc @kemais_ehlers @gitlab-com/gitlab-ux
issue