Settings upgrade

[Helium314]

A big step towards #1109, and fixes #507 with the search field

This PR is a complete re-write of the settings in compose.
The current Settings based on Android(x) preferences are very unflexible when it comes to tuning the screens, and it's very easy to get into a mess with weird sizes, paddings and whatever. Compose allows for more flexibility and does not require splitting everything in multiple parts (style and pref screen in xml, pref fragment in code).
Compose also has some drawbacks:

• Performance (mostly loading times) is clearly worse than the old view system. This is especially noticeable in debug builds, but to some extent in release builds too. But loading times are still good enough for normal use, even on my S4 mini.
• App size is increased by 1.5 MB, which is a considerable chunk. But the more convenient development is worth it in my opinion, plus the users running after Google's latest trends get their beloved Material 3 theme (sorry, but I developed an aversion against all the do-that-because-google issues).
• Stack traces are ridiculous, 80 lines is quite normal now.

Currently there are only 2 simple settings screens rewritten, but the rest is coming soon.
A core part of this PR is the central part containing all settings (working name AllPrefs). Here each preference can be added in a much more contained way than previously.
The preference screens simply get the individual prefereces from there by the settings key, and only need little additional code such as when to hide specific elements.
A search field (icon in top bar) allows filtering AllPrefs by title and description / summary. The field also allows testing the keyboard everywhere.
The preferences are recomposed on settings changes, so there is no need to keep track of changes in the current screen.

In the current state the old settings are accessible too, for easier comparison and also because not all screens are re-done.

The "only" thing missing is implementing the remaining screens, but that's quite a bit of work considering some specialized element like the SeekBarDialogPreference, the reorderDialog, or the whole language settings.

[Helium314]

This part is mostly done now, color and language settings will be done separately.

[Helium314]

Old settings still exist for comparison, will be removed later.