[Taranis] Issue #554 Radio part done. We have now modes on trims.

Let's say we are configuring the Rudder Trim on phase 1:
- R:0  => Rudder trim = Rudder trim(phase 0)
- R+0  => Rudder trim = Rudder trim(phase 0) + Rudder trim(phase 1)
- R--  => Rudder trim is OFF

Still needs to be done:
- The result on screen is awful. I need ideas. Martin?
- Companion conversions / UI for this feature
- R+1 when configuring Rudder Trim on phase 1 should be impossible
[Taranis] Issue #554 - Default is now :0 (all trims linked to the
default phase)
[Taranis] Issue #554 - Bug fixes (radio part)