* Add a locheck pre-build step to find all .strings errors.
* Treat locheck warnings as errors.
* Install mint on CI and pin locheck version.
* Clean up localised strings with invalid formatting
- Add missing screen states.
- Detect the bottom of the screen list and stop scrolling if screen state wasn't found.
- Remove unimplemented tests to speed up the run.
- Remove failed button checks in MatrixItemChooserUITests