Missing keycodes: `KC_MCTL` and `KC_LPAD`

[Dreista]

These were added as basic keycodes. See qmk/qmk_firmware#19884 for details.
Currently on vial-gui they are simply shown as 0xc1 and 0xc2. I guess we probably need to handle this?

[shadow-absorber]

KC_SYRQ also seems missing and has to be assigned using the hex code instead