Refactored repo for easier modifications

[joreeves]

I've refactored the repo to match the MOPs structure. This uses a package.json file to set environment variables. Notably this means the GOOGLE_MAPS_API_KEY can be set just once in the .json file. This also means that the external python scripts do not need to be set relative to the .hip file.

Some other benefits and ideas:

• Add a button to Refresh the Earthmesh node so it's not always trying to reload if it hits the max mesh limit
• There's probably a way to get the stats from google on how many calls have been made. Might be useful to have a hard limit set for all calls so you don't get charged if you go over each month. I setup an automatic report to warn me if I use 25%, 50%, 90% of the free teir.
• Mulithreading - part of my reasoning for refactoring was making the code more friendly to multithreading. This would speed up the processing time significantly. (may need to check if google has some max requests per minute limit)

Feel free to merge this or rebuild it yourself as best makes sense. Thanks for making this available and great work!