Make GalaxyMapPanel show suspected flight paths if options().selectedTrackUFOsAcrossTurns() enabled

[dHannasch]

Still only flight paths to player colonies, for now. Still, this shows flight paths without the player needing to click a specific ship, so this is now a noticeable change to gameplay; it'll jump out at you.

You can see here how some, but not all, flight paths are displayed: The highlighted transport is the only transport of size 33 in Deep Space Scanner range, but it only entered scanner range this turn, so its trajectory is not yet known. Next turn, its trajectory is known: Meanwhile three more transports have just passed into Deep Space Scanner range on the right, but their flight paths are not yet shown, just as the 33 transport didn't have a known trajectory last turn.

(You can also see here that this still doesn't show the destination in the transport panel on the right; I'm not sure whether I'm at peace with using the regular ETA text or whether I should make a special "We think the destination is such-and-such but technically this is just a guess and it might actually pass by such-and-such to a destination further along." In normal galaxy shapes I think it will basically never come up, but there's probably some galaxy shape with a ton of collinear systems so that the guesses would be often wrong.)

This also moves the pathSpriteTo() function up to be a default in Ship; this function was 100% identical between Transport and ShipFleet, except for being private in Transport.

[BrokenRegistry]

I'm not sure whether I'm at peace with using the regular ETA text or whether I should make a special "We think the destination is such-and-such but technically this is just a guess and it might actually pass by such-and-such to a destination further along."

I'd suggest the regular text with "?" before or after the value!

[BrokenRegistry]

Comment from Xilmi: I think some of the things he coded don't work quite properly. I think what he wanted to achieve is that you get a "where the enemy is flying"-line based on tracking their position the turn before and then calculating where that goes to.

This works really inconsistently and sometimes also shows them to fly to a system that they are retreating from. Overall it's more confusing than helpful the way it currently is. It's almost like 1/3rd chance it works as intended, 1/3rd it doesn't work at all and 1/3rd it shows the ship flying in the wrong direction