cursor-jump feature

[thartbm]

[Non-preferred enhancement]

Add an option to have the cursor be aligned in the first X% of the home-target distance, and then "jump" to whatever rotation the trial used. A tickbox to activate it, and a slider going from 5% to 95% in steps of 5% to control it. Should work with all other features and the settings should stored in the JSON. The % at which the jump occurs should be stored in the data (empty or NaN when off) and not interfere with data processing.