MP Action tools "set waypoint" no work if it's set before arming

Idea is when mission is to long, and when copter battery failsafe trigger RTL, copter land and we reset it changing battery, it would be great to set new start waypoint from mp, without remake flight plan.

Also, it would be great that last commands like TAKEOFF, DO SET ROI, DO SET CAM TRIGG DIST will be automatically invoked to resend automatically the drone at this waypoint in the same configuration than when failsafe was invoked for do the work without remake the flight plan.

The issue proposes setting a new start waypoint after battery-failsafe RTL and replaying prior commands such as TAKEOFF, DO SET ROI, and DO SET CAM TRIG DIST. Define the expected behavior and safety boundaries first, then identify the Mission Planner mission and failsafe entry points; done means the workflow works without rebuilding the flight plan.

Written by the indexing model from the issue text.