### Tasks
- [ ] Create abstract base class `MacosProgressIndicator`
- [ ] Rename `ProgressCircle` to `MacosCircularProgressIndicator`
- [ ] Style `MacosCircularProgressIndicator` according to [latest design](https://www.figma.com/file/IX6ph2VWrJiRoMTI1Byz0K/Apple-Design-Resources---macOS-(Community)?node-id=121%3A12174&mode=dev)
- [ ] Rename `ProgressBar` to `MacosProgressBar` and style according to [latest design](https://www.figma.com/file/IX6ph2VWrJiRoMTI1Byz0K/Apple-Design-Resources---macOS-(Community)?node-id=121%3A12174&mode=dev)