Reimplement frontend tests with cypress

[SamuelWei]

Partially implements #1150 Implements #721 Implements #722

Type (Highlight the corresponding type)

• Bugfix
• Feature
• Documentation
• Refactoring (e.g. Style updates, Test implementation, etc.)
• Other (please describe):

Checklist

• [x] Code updated to current develop branch head
• [ ] Passes CI checks
• [x] Is a part of an issue
• [x] Tests added for the bugfix or newly implemented feature, describe below why if not
• [x] Changelog is updated
• [ ] Documentation of code and features exists

Changes

• Add frontend tests for Login, Logout, Locales
• Add frontend tests for Room Index page
• Add frontend tests for Room page
• Add frontend tests for Room Members Tab
• Add frontend tests for Room Settings Tab
• Add frontend tests for Room Files Tab
• Add frontend tests for User Profile