tvOS topic gradient colors

What's Changed

Improvements

• Update design system (PLAYRTS-5514) by @pyby in #468
• Show header update with topic gradient (PLAYRTS-5405 & PLAYRTS-5478) by @pyby in #451
• Implement navigation from swimlane to micropage (PLAYRTS-5527) by @mutaben in #479

Fixes

• Fix cell image background (PLAYRTS-5510) by @pyby in #476

Maintenances

• Update romansh translation by @pyby in #480
• Fix linter with SwiftLint 0.55.1 by @pyby in #484

CI and dev tools

• Update pull request template by @Loic-Dumas in #467
• Update PR template by @mutaben in #472
• Update to Xcode 15.3 by @mutaben in #473
• Update LicensePlist version by @pyby in #474
• Update Cocoapods version by @pyby in #475
• CI: clean untracked files when an error occurred by @pyby in #482
• PLAYRTS-5534 Enable SwiftLint in iOS and tvOS targets in debug mode by @mutaben in #483

New Contributors

• @Loic-Dumas made their first contribution in #467
• @mutaben made their first contribution in #472

Full Changelog: tvos/1.8.5-451...tvos/1.8.6-454