Improve Sync (and its UX)

There are a few issues with sync to tackle, some functional and some user experience)

We've had a lot of data-model related changes in the past 1.5 years and users who were there before are more likely to be affected.

• (In progress) Show download counter in desktop and mobile

  • Was removed and needed reimplementation with Important: Manifest V3 Update in Chrome - Extension 3.18.0

• (In progress) Space associations not properly syncing over from mobile to extension

• (Up Next)

  • Mobile app sync seemingly stuck at "preparing sync" step on the very first sync with lots of data

    • It's actually syncing but because we have an old Firebase SDK version we can't easily update we can't really count the items properly.

    • Solution right now:
      Just let it open and syncing, it should eventually just finish.

  • Rare instance: Setting up new extension with data that is older than 6 months has data related issue because of recent and frequent data model updates