Feature Request: reverse scroll mission list on system with right-click

[redcrate]

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name: Feature Request: reverse scroll mission list on system with right-click

Describe the feature-request
when clicking on a system to see the missions available, left click goes down the list of available mission, right click should reverse scroll this list

To Reproduce
Open the map
click on a system with more than one available mission
click again to go to the next mission in the list for that system

Expected behavior
click on a system with more than one available mission
click again to go to the next mission in the list for that system
right-click to go to the previous mission in the list for that system