Created new `suite_messaging` where all related chat tests will be migrated to.
- `tst_ChatFlow` has been moved to new `suite_messaging`. It still contains some broken tests.
- `tst_groupChat` has been moved to new `suite_messaging`. It is now working (but it relies on the mailserver so could fail sometimes).
- `tst_statusLoginPassword` has been moved to new `suite_onboarding`.
- It has been needed to move some object definitions from `chat_names.py` to `global_names.py` since they are shared between different suites.
- Some other minor object and steps definitions have been moved to fit with the new structure.
Closes#7624
Noelia