Part of #15190
WPKit PR: wordpress-mobile/WordPressKit-iOS#339

Decription:

• Update fix threat button to trigger fix threat request
• Update ignore threat button to trigger ignore threat request

To test:

Fix threat

1. Launch the app, tap on the My Site, tap on a site with Jetpack Scan and also has Threats
2. Tap on a threat cell
3. Tap Fix threat button
4. ✅ Fix threat alert is displayed
5. Tap Cancel button on alert
6. ✅ Alert is dismissed
7. Tap Fix threat button, then tap OK button on alert
8. ✅ Should navigate back to the Scan screen
9. After about a minute has passed, pull to refresh
10. ✅ The fixed threat no longer shows up
11. Tap on History > Fixed tab
12. ✅ The fixed threat shows up in the Fixed tab

Ignore threat

1. Launch the app, tap on the My Site, tap on a site with Jetpack Scan and also has Threats
2. Tap on a threat cell
3. Tap Ignore threat button
4. ✅ Ignore threat alert is displayed
5. Tap Cancel button on alert
6. ✅ Alert is dismissed
7. Tap Ignore threat button, then tap OK button on alert
8. ✅ Should navigate back to the Scan screen
9. After about a minute has passed, pull to refresh
10. ✅ The ignored threat no longer shows up
11. Tap on History > Ignored tab
12. ✅ The ignored threat shows up in the Ignored tab

Example screenshots:

Fix threat	Ignore threat

PR submission checklist:

• I have considered adding unit tests where possible.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.