Keymap: simplify default keymap for paint modes
Part of design task #105298 to improve overall consistency.
This removes various shortcuts unused or blocking shortcuts:
- Brush tool shortcuts
- Mesh sculpt mode shortcuts
- `X` = Draw
- `Shift S` = Smooth
- `P` = Pinch
- `I` = Inflate
- `G` = Grab
- `L` - Layer
- `Shift T` = Flatten
- `C` = Clay
- `Shift C` = Crease
- `K` = Snake Hook
- `M` = Mask
- `D` = Gpencil Vertex Paint - Draw brush
- Duplicate dyntopo shortcut for editing detail size
- Grease Pencil: Undocumented draw tool specific guide shortcuts:
- `O`, `J`, `Alt J`, `K`, `Alt K`, `Shift K`, `L`, `Alt L`, `Ctrl L`,
`V`, `M`, `C` & `Alt C`
- `L` = Gpencil: "Alternate" operator shortcut
Also moved erasing box and lasso gesture shortcuts out of specific tools
and into the Draw mode overall.
Ref !108712.
a7dd864dcf