Lag Spikes after FutureChunk commit

[jlitewski]

With the current rough implementation of FutureChunks, it causes lag spikes because I haven't fully coded in the required checks to prevent them from halting the main thread while they load if any function is called that requests the underlying ChunkData class.

• Fully Implement all needed FutureChunk checks to reduce or remove lag spikes
• Rewrite any needed functions to better integrate FutureChunks
• Rewrite FutureChunks to implement IChunk instead of extending Chunk