Refine water shinecharge return in Oasis, Precious, and West Sand Hall Tunnel

[blkerby]

These are essentially copied from the bottom-left Aqueduct strats, with a few necessary adaptations:

• In Oasis and West Sand Hall Tunnel, for the 1-tile runway variation, we have to unlock the opposite door.
• In West Sand Hall Tunnel, we have to kill the crab in the left-to-right strats. I checked that right-to-left there is time to jump over the crab (tested with 1-tile and 5-tile runway variants).
• In Precious Room, there's no 1-tile runway variation since there's not enough space; you would run into the wall before being able to gain the shinecharge.

In all of these, I removed the existing "Leave Shinecharged" strats. These started from a shinecharged junction node, and the location of the node is not defined precisely enough to use for this (i.e., since the exact location where you stop depends on the runway tiles used, which affects the frames remaining). So the new strats just go from the door node to itself, like the ones in Aqueduct. The shinecharged junction nodes are still used for the other existing strats, e.g., ones that perform a spark or chain temporary blue, since for those ones the exact location where you gain the shinecharge is unimportant.