lockscreen: Rework and simplify keypad appearance, and fix lockscreen state
The current lockscreen mockups were originally from this mockup: https://phabricator.kde.org/T12717
There are some issues with it however:
- The 0 key is on the right, which is a bit strange and differs from the layouts of all other platforms
- One-handed usability is worse due to 4 columns instead of 3
- Most mobile lockscreen have the keypad toward the center for one-handed usability, our keypad is stuck to the bottom
- It makes use of a lot of shadows which makes it slower to load
- It's supposed to emulate the design of the keyboard, but it doesn't look like it so it's out of place
The new design is much simpler, with a centered 3 column approach making keys much easier to reach with one hand. It also avoids the use of shadows and layers.
TODO:
- Investigate some improvements for keyboard input