Feature Request: Panel client area internationalization

[mechite]

This is related to #2518.

It proposes localization of the panel client area.
This proposes adding the following personal preferences configuration:

This feature was available in 0.7x and removed in 1x to reduce complexity.

[DaneEveritt]

Yeah, the good news is that we've got the foundation pieces in there since it was needed for the activity log. It is just a lot of areas to cover — I'm not entirely sure it makes sense to have an issue tracker ticket for this, but if someone wants to open a PoC PR on a simple account page showing this working I think that would be a solid start, and allows us to figure out the minor details in a more contained set of work (versus doing the entire front-end in one sweep).