Fix a timewarp kraken, and some other changes to setting the time in simulations

[Clayell]

Fix #2364.
Currently, only inputting Hours:minutes:seconds into the simulation window passes through TryParseTimeString without any failures as expected, but this leads to some problem later down the line where the game starts timewarping rapidly (2364). This PR makes it so if the user is trying to specify a specific time, they must include the YYYY-MM-DD as well to avoid this error. (only putting in YYYY-MM-DD and not the HH:mm:ss is currently fine, as it just sets the time to midnight) All other formats should still work.

Also remind the user that they are allowed to specify seconds in that format, as it can be parsed perfectly fine.

RIP analemma

[Clayell]

Also also remind the user that they can just specify time in seconds.
Not actually sure if this works, or if I even put in the right amount of seconds for the example (I used 1960-12-31 23:59:59 and changed it to seconds). Someone please double check.

[Clayell]

Hm, on second thought, I think the format that is allowed should changed based on whether or not "From now" is selected.
If "From now" is selected, then it will refuse values in format "1960-12-31 23:59:59", and change the tooltip.
If "From now" is not selected, then it will accept values in all of the formats, and change the tooltip. (still disallowing "23:59:59", but allowing "1960-12-31")

Otherwise, we could end up with some really wacky situations, where people put "1960-12-31" and accidentally hit "From now", resulting in them warping forward 1960 years.