Import/Export sound packs

Problem

Importing sounds for notifications one-by-one is tedious if you're trying to share sounds with friends or others online.

Proposed solution

Add the option to export the sound files as a zip, where each file is named based on what notification sound it replaces. Then, other people could import that zip at once to replace all their sounds.

Notes (optional)

It'd also just be useful for keeping a personal collection of sound packs and swapping them out whenever you want. I think it goes along well with the idea of the custom themes, and would enhance the ability for people to share their customizations with others and personalize their experience!