v6.0-strobe-2022-11-15

This is a change to enable than adding a Strobe blink as a new overlay, similar to iNavFlight#8531

ledConfig_t had no bits free to add new overlays, requiring it to be changed packed struct. which ends up being 40bits (as compared to the current 32).

This change introduces a new 'E' overlay for strob'E' which can be enabled as follows from the cli.

You have 2 leds in your chain, you can use the following command to set them as navigation + strobe lights:

# Led 0, Color + Strobe, Color 5 (green)
led 0 0,0::CE:5
# Led 1, Color + Strobe, Color 2 (red)
led 1 0,1::CE:2

New MSP commands have been added to GET/SET leds and the old MSP command is still supported, but won't allow you to set the strobe mode.

A corresponding pull request for the configurator has also been added that uses the new MSP commands and allows setting the strobe overlay from the usual led UI.