Fix #7828: Adding Issue Category Separately to VPN Contact Form

[soner-yuksel]

Summary of Changes

Adding issue selector as mandatory for support, check the ticket for implementation details.

This pull request fixes #7828

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()
• New or updated UI has been tested across:
  • Light & dark mode
  • Different size classes (iPhone, landscape, iPad)
  • Different dynamic type sizes

Test Plan:

1. Go Settings
2. Press Brave Firewall + VPN
3. Press Contact Technical Support
4. Choose (toggle) categories which are necessary
5. Click Continue to Email
6. Issue Selection screen presented
7. Select a issue
8. User email should be presented with necessary Issue in subject and body for the email

Screenshots:

RPReplay_Final1691096266.MP4

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue and pull request is assigned to a milestone (should happen at merge time).