Bringing parity back for pathfinder, movement and a number of find APIs.

[Azaril]

• Cleanup duplicated traits across structures.
• Move to using serde-wasm-bindgen instead of built-in bindgen serialization that uses stringification + JSON parsing.
• Implement pathfinder functions back to parity including options callbacks.
• Implement typed find methods. (Still missing 'Terrain' find.)
• Add strongly typed wrapper containers for 'Array' and 'HashMap' JS objects.
• Add 'as_has_store' back to structure enum type. (Other traits need adding still!)
• Add missing structure properties.
• Remove old stdweb code for functionality that is now implemented.

NOTE: This is not very well tested as there's a lot of surface area missing just to get back to parity. Once parity for critical functionality is done it will be simpler to test with existing bots.