Massive click code rework by SuperSayu, ported from TG.

Full details at https://github.com/tgstation/-tg-station/pull/1206
Fixes #3648

Signed-off-by: Mloc-Argent <colmohici@gmail.com>
Holding down Alt or Alt-Gr and clicking a tile will now bring up a stat panel with everything in that tile listed.

Full credit goes to SuperSayu.
https://github.com/tgstation/-tg-station/pull/1402

Signed-off-by: Mloc-Argent <colmohici@gmail.com>