App Re-Vamp

This is a big Re-Vamp of the entire App. A lot has been changed and improved.

Changelog

Improvements

• Lots of Code Refactoring.
• Upgrade JDK version.
• Upgrade Gradle Version.
• Upgrade from Kotlin Synthetics to Jetpack View Binding.
• Improve Gitlab CI pipeline setup.
• Fix Warnings about Deprecations and other issues.
• Grab Website favicons through DuckDuckGo, instead of Google.
• Do not show Notifications while App is in Foreground.
• Show only a single notification, if more than one website is not reachable. (Do not show 10 Notifications for 10 unreachable Websites.)
• Overhaul metadata, like UI Strings, etc.

Features

• Enable Drag & Drop to re-order WebsiteEntry in WebsiteEntry list UI.
• Add itemPosition to WebsiteEntry data structure, to enable user-defined entry positions in WebsiteEntry list UI.
• Make Room Database Auto-Migration possible.

I am open to discuss decisions made here. I tried to make them very agreeable, though.

I would recommend to at least bump a feature version. So, if we are at version 1.1.2, it would be reasonable to bump it to 1.2.0. It could even be bumped to 2.0.0, due to the database schema change and amount of changes. Though, all this should be backward compatible, especially due to the newly implemented Room Database Auto-Migration feature.