Added an upgrade function to fix renamed behavior nodes in the unlikely
event that someone was changing behavior settings this way instead of
using references.
Moved the keymap upgrader to a top-level page like the power profiler
to make it more discoverable. It upgrades more things than key codes
now, so putting it in the codes category doesn't make much sense.
Converted the upgrader code to TypeScript and split it up into smaller
files to make it easier to add new upgrade functions.
Added upgrade functions to remove/replace "label" properties and rename
matrix-transform.h to matrix_transform.h.