Now it is possible to use ModTap and LayerTap keys as part of combos.
Overlapping combos also don't trigger all the combos, just exactly the
one that you press.

New settings:
- COMBO_MUST_HOLD_MODS
- COMBO_MOD_TERM
- COMBO_TERM_PER_COMBO
- COMBO_MUST_HOLD_PER_COMBO
- COMBO_STRICT_TIMER
- COMBO_NO_TIMER

This in the end actually saves space as the members are accessed so many
times. The amount of operations needed to access the bits uses more
memory than setting the size saves.

…mbos

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Stuff combo's `disabled` and `active` flags into `state`. Possibly can
save some space.

- Simple examples now has a combo that has modifiers included.
- The slightly more advanced examples now are actually more advanced
  instead of just `tap_code16(<modded-keycode>)`.
- Added a note that `COMBO_ACTION`s are not needed anymore as you can
  just use custom keycodes.
- Added a note that the `g/keymap_combo.h` macros use the
  `process_combo_event` function and that it is not usable in one's
  keymap afterwards.

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

No need to call `dump_key_buffer` when disabling combos because the
buffer is either being dumped if a combo-key was pressed, or the buffer is empty
if a non-combo-key is pressed.

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>

Co-authored-by: precondition <57645186+precondition@users.noreply.github.com>