Add "absolute calculation" to RGB effect and speed behavior bindings

[petejohanson]

As part of the behavior locality work, we added ability for a behavior binding from "state relative" to "state absolute", and updated many behaviors to add the necessary callbacks.

One behavior not updated full was the RGB Underglow one, in particular:

• Effect forward/backwards
• Effect speed selection

Are not currently made absolute based on the current state of the central.

This needs adding to the on_keymap_binding_convert_central_state_dependent_params function in app/src/behaviors/behavior_rgb_underglow.c file.