General code cleanup task

[jmrog]

In some cases, functions return with a large block wrapped in new Promise((resolve, reject) => { . . . }, when it probably isn't necessary (I'm not sure because I'm basing this on memory alone right now) to wrap the whole block like that. This could be cleaned up. Also consider using async/await.

[jmrog]

Additionally, there are unnecessarily verbose index.ts files used just for exporting. They import first and then export, when they could simply just export directly from the files.

[jmrog]

More: some of the code could use better typing.