Gugal 0.9 - the long-awaited update.

This update brings many quality of life improvements and new useful features to the app, as well as a minor facelift. It also updates many things in Gugal's code as we head towards a stable release.

App:
- The app now notifies users if there is no internet connection.
- Now built for Android 15.
- The search page has been slightly updated to fit more content.
- The new backup and restore feature allows users to back up Gugal's data and optionally encrypt the backup with a password. The backup format is documented on Gugal's website.
- The search bar can now be moved to the bottom of the screen for a more comfortable user experience.
- Simple builds are no longer available.
- Gugal now supports Android's web search action, adding support for more launchers.
- The system theme can now be selected on Android 9.
- News now comes first in the navigation bar, if it is enabled.

Search engines:
- Gugal now supports Stract, an independent, open-source search engine.
- SearXNG/searx instances that require HTTP authentication are now supported.

For developers:
- SERP providers can now request extra authentication, such as API keys and login credentials.
- A full API reference is available on the Gugal site, to complement the documentation.
- Gugal now includes the M3X library for extra Material 3 inspired components.
- All libraries used in Gugal have been updated.
- SERP provider results can now have rich formatting with AnnotatedStrings.
- A development provider has been added for testing annotated search results.
For more information, read "SERP provider API changes" on the Gugal site.
