Implemented enhancements:
- In create screen make option to make Billable status to not billable #2779
- Make billable field batch editable #2694
- Timesheet uncheck billable by default #2625
- API: Add customer number to customer collection #2358
- improve billable flag #2851 (kevinpapst)
- refactor system configuration title and wording #2847 (kevinpapst)
- Translations update from Weblate #2823 (weblate)
Fixed bugs: