TimeScan: Add Solar Arcs to Midpoints

Noel would include solar arcs to midpoints in his searches. Need to add them here as well.

Hiroki: Hey you might have this in your plans already, but could you consider adding "Solar Arc to Midpoints" to show in the Timescan of APG? Noel used it and I think there is a lot more we could do with midpoints if we incorporate it in timescan (similar to how useful it is to have the sun/moon midpoints in timescan). 7/29/23