Adjusted the colors of the notifications and media controls to help them fit in better together.


Clock position changed so that it will always be at the top.
The login keypad will now hide when the keyboard is opened.

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