Ensure the Truffle Project Loader can be loaded in both development and production

[mikeseese]

Fixes https://github.com/trufflesuite/ganache/issues/1141

trufflesuite/ganache@7042edd introduced a bug for production (but not development) builds. The commit changed the way Truffle projects were loaded by running a completely separate node process thats installed on the user's machine to make sure that the node that was loading the Truffle project would be the same version that the Truffle project was "compiled" against.

Unfortunately the directory structure built with asar packing in production doesn't actually exist on the disk so the location can't actually be loaded by node. First we needed to specify that the project loader gets unpacked to the disk by adding it into the build.extraFiles config in package.json. Then we needed to use electron.app.getAppPath() instead of __dirname to find where the source code is located. This folder is the base root of the repo in dev mode, but it actually points to resources/app.asar in production, which is why we needed to add a ../.. to the path to get to the root folder.

I achieved this through passing environment variables to the child. An interesting fun fact is that I originally didn't have ...process.env, but the PATH environment variable wasn't passed to the child so it couldn't find node; so if you provide options.env to the spawn, you have to make sure to provide everything that's needed (which makes sense, but was scratching my head for awhile)

[honestbonsai]

LGTM