[Keymap] Initial personal keymap for Lily58 (#6908)

[Keymap] Initial personal keymap for Lily58 (#6908)

* Initial Lily58 keymap

* Still not sure if these thumb key placements are optimal or not. I
might want to move space (enter) one key to the left (right),
respectively.

* Also unsure how I feel about Esc on a mod tap key with Ctrl... might
move it back to its own key and relocate the = key.

* Missing bindings for Print Screen, Scroll Lock, Pause/Break.

* Make Lily58 layout support operation without numrow

* Move some Lily58 modifiers around

* Move nav keys to more consistent locations

* Rebinding shift on Raise is stupid

* Don't stomp Ctrl on the Lower layer

* Tweak bottom row a little bit