* refactor: convert channels/channel/ files to ts
- convert js files to typescript
- update types
- fix lint issues
Fixes: 21299
* fix: solve lint issues channels/channel
- fix lint issues
- udpate types
* fix: adjustment to test case MM-T1687
- code reorganization for test case MM-T1687
* fix: update types on function apiCreateCustomAdmin
- update types for apiCreateCustomAdmin on user.d.ts so that
lint issue is solved