AP-5474: Add start date for MTR-A feature flag

[colinbruce]

What

Link to story

This adds the following start date to each environment:

• UAT: 6 November 2024, as the date has passed, it will be enabled immediately the switch is enabled
• Staging: 12 November 2024, allows testing before the meeting on the 13th
• Production: 20 November 2024, actual release date
  The application will fallback to the 20th November in case an environment variable gets deleted or corrupted

The Setting model is updated to check for the radio button being set to true and the current date being equal to, or greater than, the start date

It also displays the date on the admin page for confirmation

Checklist

Before you ask people to review this PR:

• Tests and rubocop should be passing: bundle exec rake
• Github should not be reporting conflicts; you should have recently run git rebase main.
• The standards in the Git Workflow document on Confluence should be followed
• There should be no unnecessary whitespace changes. These make diffs harder to read and conflicts more likely.
• The PR description should say what you changed and why, with a link to the JIRA story.
• You should have looked at the diff against main and ensured that nothing unexpected is included in your changes.
• You should have checked that the commit messages say why the change was made.

[naseberry]

👍

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud