Odd RTH and Manual mode behaviour during WP mission

[breadoven]

Current Behaviour

If RTH mode or Manual mode is selected when flying a mission you end up locked in RTH mode until WP mode is deselected. This is a little confusing especially where Manual mode is concerned because you expect to regain full manual control in this situation not find yourself in a different automated Nav mode.

Steps to Reproduce

1. Fly mission by selecting WP mode
2. Select RTH mode or Manual mode - RTH activates
3. Deselect RTH or Manual mode
4. RTH remains active
5. Deselect WP mode - RTH stops

Expected behaviour

Maintaining RTH until WP mode is deselected is understandable if RTH mode has been selected during a WP mission but the situation with Manual mode doesn't make sense. Seem to remember that pre 2.6.0 switching to Manual during a WP mission gave you Manual mode not RTH. Not sure why why this was changed, oversight or intended ?

Suggested solution(s)

The following needs to account for Manual mode being selected so it doesn't trigger RTH instead.

inav/src/main/navigation/navigation.c

Line 3151 in 198b4f2

if (IS_RC_MODE_ACTIVE(BOXNAVRTH) || (IS_RC_MODE_ACTIVE(BOXNAVWP) && !canActivateWaypoint)) {

[breadoven]

Source of this change:
#5997

Changing the code as follows would ensure Manual activates when selected during a mission, not RTH:

if (IS_RC_MODE_ACTIVE(BOXNAVRTH) || (IS_RC_MODE_ACTIVE(BOXNAVWP) && !canActivateWaypoint && !IS_RC_MODE_ACTIVE(BOXMANUAL))) {

Also if Manual was subsequently deselected you would end up in RTH if WP mode was still selected which would be OK so long as there was something to indicate the RTH was caused by the fact WP mode was still selected. Given that WP mode is latched off once interrupted by RTH or Manual mode selections perhaps it just needs a system message displayed to indicate WP mode needs to be reset to cancel the RTH. This is probably a better solution than displaying the flight mode in the OSD as "WRTH" as suggested in #6524.