make plane landing route as separate icon as land command instead of do it it waypoint

#### Issue details
right now for plane we have to add a takeoff command at 1st way point and landing command at last way point to execute the auto takeoff and landing.
if landing route is independent with way point it will be better to activate auto landing command whenever user want ,remaining time will have auto mode .

Takeoff also to be independent command as takeoff icon after takeoff finished it should loiter automatically with user entered value until user give next command so it will easy to operate the mission with out add extra way point on the flight plane page.

its suggestion only

#### Version
_What version was the issue encountered with_

#### Platform
[ ] All
[ ] AntennaTracker
[ ] Copter
[ ] Plane
[ ] Rover
[ ] Sub

#### Airframe type
_What type of airframe (flying wing, glider, hex, Y6, octa etc)_

#### Hardware type
_What autopilot hardware was used? (pixhawk, pixracer, PX4FMU etc)_

#### Logs
_Please provide a link to any relevant logs that show the issue_

The issue names no files, tests, or entry points. First clarify the desired Plane takeoff and landing command behavior, including the automatic loiter state and how separate icons should operate, then identify the Mission Planner UI and mission-command areas involved and define acceptance tests for those workflows.

Written by the indexing model from the issue text.