Add "Forced ON" toggle to sf backlight

[pitts-mo]

Is there an existing issue for this feature request?

• I have searched the existing issues

Is your feature request related to a problem?

To reduce power usage and light pollution I (and my friends) set backlight to Keys, 5s, and a minimum brightness. eg:

Yet, There are many times where I also needed the backlight to stay on for extended periods of configuration & testing as well as being brighter for finding a model on a bight sunny day. However, the backlight fixes of v.2.6.x also introduced a new conflict in handling of the old special function backlight that remains unresolved.

Describe the solution you'd like

Please add a "Forced ON" boolean toggle within special function backlight so that the backlight can forced ON and simultaneously allow the brightness to be control while the function is active.

This issue is observed on both B&W and Color radios.
FrSky X9D+
Jumper T16
RadioMaster TX16S
RadioMaster MT12

Describe alternatives you've considered

EdgeTX 2.10.5 allows one to do these desirable things:
-always active function to adjust brightness of a backlight that is already ON (active) using a knob:

-force backlight to always stay ON when function is activated by a switch:

-only adjust brightness of a backlight that is already ON (active) using a knob while function is activated by a switch:

Unfortunately, Since EdgeTX v.2.6.x I have been unable to find a way to configure EdgeTX as to allow the backlight on via a switch while also adjusting the backlight brightness.

Additional context

The many other EdgeTX issues referencing backlight that appear to be more concerned with the ability to dim the backlight completely OFF. I wonder if some of those users might find it almost as helpful to set backlight timeout very short and then force the backlight ON to the desired brightness with the special function.