Gate importing

[Divran]

TODO List:

• Make upload code able to handle more than 64kb data
• Possibly move import feature to a different key (currently right click on a gate)
• Make it not require clicking directly on a gate - just anywhere on a contraption that contains gates should be enough
• Add TOOL.Information description to let people know the feature exists
• Currently the angle of imported gates is based off of one entity in each "plane". This can result in the import being at a strange angle. Possibly fix by rotating to match player's angle or similar. Not very important.
• Zoom code to allow very small nano scale gate setups to be imported isn't very good. Not sure how to improve.
• Remember to place E2's getConnectedEntities function and buildFilter function in the E2Lib table for global access (this PR won't work without it)
• run PP CanTool checks for every entity that's imported

[Divran]

Here's some pictures

[Denneisk]

I hate to ask but is this PR still relevant?