[Feature Request] Concurrent Downloading/Processing

[bransoned]

Is your feature request related to a problem? Please describe.
Download and processing are done sequentially which is quite slow, especially for large Memory imports

Describe the solution you'd like
Introduce multi-threading to the memory_download() function to download and processes multiple files concurrently.

Describe alternatives you've considered
Async functions? Seems more difficult to try and implement than multi-threading.

[bransoned]

Was thinking about this problem some more. Would take some restructuring of the scripts logic. Easiest implementation would most likely be to download all files concurrently first, then process all files (either concurrently or sequentially).

I think I could add on to the "memories" dictionary in parse_snapchat_memories() to add more flags to account for processing/downloading checks on individual files. Or just implement a full file-tracking DB described in #10.

[bransoned]

I think switching from the "requests" library to the "aiohttp" library would give good and scalable results for concurrent downloads.