Clean up gate code to match base hex teleport rework

[Robotgiggle]

• Fixes Using gates crashes the game with latest hex #183
• Removes the 32768 block teleport limit from gates, since that was removed from base hex in the 1.20 update
• Fixes some issues with entity-stack teleporting via gates to align with similar changes in base hex
• Properly implements the entity-stack preservation mechanism so stacked entities will remain so if they're all gated at once

[Robotgiggle]

Had an idea for a cleaner stack-teleport system, will try to implement tomorrow.

[object-Object]

LGTM