Language selector now under feature flag

[frimpongopoku]

Language selector is now under feature flag 🌚 . Super robust feature flag implementation 🌚 !

What kind of change does this PR introduce? (check at least one)

• [x] Bugfix
• [x] Feature
• [ ] Performance improvement
• [ ] Feature removal
• [ ] Code style update
• [ ] Refactor
• [ ] Docs
• [ ] Build-related changes
• [ ] Other, please describe:

Does this PR introduce a breaking change? (check one)

• [ ] Yes
• [X] No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• [ ] It's submitted to the dev branch or to a feature branch, not the main branch
• [x] When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
• [ ] All tests are passing: https://github.com/massenergize/massenergize-campaigns/blob/main/.github/CONTRIBUTING.md#development-setup
• [ ] New/updated tests are included

Other information: