Modal Widget

[rubuy-74]

Closes #1296 Modal Widget for the app's redesign.

Review checklist

• [ ] Terms and conditions reflect the current change
• [ ] Contains enough appropriate tests
• [ ] If aimed at production, writes a new summary in whatsnew/whatsnew-pt-PT
• [ ] Properly adds an entry in changelog.md with the change
• [ ] If PR includes UI updates/additions, its description has screenshots
• [ ] Behavior is as expected
• [ ] Clean, well-structured code

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 16%. Comparing base (c26b4fd) to head (00bff18). Report is 7 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #1298 +/- ## ======================================= Coverage 16% 16% ======================================= Files 233 233 Lines 7214 7214 ======================================= Hits 1139 1139 Misses 6075 6075 ```