The font size of the suggested words is reduced if the word would
otherwise split on two lines.

The color resources starting with `@android:color/system_` are not
available on API < 31.

No effort is made to implement the Monet feature on Android 9. Instead,
the monet themes look like the Dark and Light themes.

The `CandidatesView` is implemented as a `LinearLayout` that is divided
horizontally with up to 3 `TextView`. It might in the future contain
buttons on the sides.

The candidate view is nested into the input view rather than using
Android's `setCandidatesView` and callbacks as the API is unreliable and
complicated.

The first suggestion goes in the middle to be more accessible. The
second suggestion goes on the right to be more accessible to the
right-handed, because it must go somewhere.

* Fix extra bottom margin when navbar buttons absent

Fix the extra space that was appearing when the gesture-navigation bar
didn't contain the "switch IME" or "close IME" buttons.
This was found on OneUI 7 with the two "keyboard key" related options
turned off.

* Remove unneeded nav bar detection and width computation

The keyboard background now extends under the system bars and display
cutout on Android 15 but the keys do not.

The back and IME switching buttons that appear in the navigation bar require
special care to not overlap with the keyboard.

The launcher and settings activity are also fixed.

This adds the clipboard pane, which allows to save an arbitrary number of
clipboards and to paste them later. The key can be disabled in settings.

Checking the "Recently copied text" checkbox will cause the keyboard to keep a
temporary history of copied text. This history can only contain 3 elements
which expire after 5 minutes.
If this is unchecked, no history is collected.

History entries can be pinned into the persisted list of pins.

Among others:
- Use `apply` instead of `commit` when saving shared preferences.
- Avoid inlined Api
- Remove unused resources

This is a new section in the extra keys option that allows to enter
arbitrary strings which are then added to the keyboard.

A new string is needed for the title of the section, Android's icons and
strings are used as much as possible to avoid adding more strings.

Keys are stored in the preferences as a JSON array of strings.

The conversion into px was done twice, leading to wrong values.