Interface language tests

[JeanneSon]

Description

The following tests have been converted to playwright

Interface Language picker (LF only so far)

✓ should be using English interface for user at Login

These tests were merged with other tests (because they were relying on each other)

✓ can change user interface language to French -> Can change user interface language to French, stays in French also on other pages, can change back to English
✓ should still be using French in another page -> Can change user interface language to French, stays in French also on other pages, can change back to English
✓ should still be using French back in the login page -> Can change user interface language to French, stays in French also on other pages, can change back to English
✓ can change user interface language to back English -> Can change user interface language to French, stays in French also on other pages, can change back to English

Type of Change

• E2E tests

Checklist

• I have performed a self-review of my own code
• I have reviewed the title/description of this PR which will be used as the squashed PR commit message
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works

[github-actions]

Unit Test Results

368 tests   368 ✔️  42s ⏱️
    1 suites      0 💤
    1 files        0 ❌

Results for commit d186bc0.

♻️ This comment has been updated with latest results.

[megahirt]

Approved with one non-blocking suggestion!