[native] Use new Alert wrapper

Summary:
Solution for ENG-4421.
This diff replaces all native Alert occurrences with a new Alert wrapper, which sets the currently selected theme as an Alert theme.

Depends on D8586.

Test Plan:
Test on iOS (setting alert theme is only supported on this platform) and on Android (to check if nothing breaks).
Prior to testing, make sure what theme you have set on iOS device. Then set app theme opposite to theme set on device. This will make sure, that Alerts use app theme rather than system theme.

Testing each location where the Alert import was replaced can be time-intensive, therefore only selected areas have been inspected to determine if the Alert function operates as expected:

• Login panel -> invalid username, empty password
• Edit message -> cancel editing
• Edit password -> not matching passwords, incorrect pasword
• Logout -> keep login info in chain alert
• Delete account panel -> invalid password
• Chat -> leave chat

Reviewers: bartek, tomek, inka

Reviewed By: tomek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8648