Server endpoints for PIN create, verify & update

[GoranPrime]

Overview

Closes: #609

Checklist

Implementation

• [x] Implementation matches ticket acceptance criteria and technical notes
• [x] Manually tested against Acceptance Criteria
• [x] UI checked in Light / Dark mode

Stability

• [x] Checked if changes affect any features and verified affected features work as expected
• [ ] Added unit tests for new code and verified existing tests work as expected

Code quality

• [ ] Updated CHANGELOG.md, README.md and package versions in pubspec.yaml
• [ ] Dependencies are updated to latest versions or new tickets are created if there are breaking changes or deprecations
• [ ] If an unrelated part of the codebase needs to be updated or refactored, create tickets with proposed changes

[codecov[bot]]

Codecov Report

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

Project coverage is 95.42%. Comparing base (9a7c3e2) to head (32d9571). Report is 6 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #790 +/- ## ======================================== Coverage 95.42% 95.42% ======================================== Files 120 120 Lines 2582 2582 ======================================== Hits 2464 2464 Misses 118 118 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.