out of date library information until page reload (indexeddb not up to date)

[simon-weber]

This can cause syncs with outdated information in a sequence like:

• open google music on device A
• make metadata changes on A
• load extension on device B
• extension on B sees pre-edit metadata
• reload
• extension on B sees new metadata

I'm not sure if there's an easy solution for this. Maybe there's a way to wait on Google to write the indexeddb (which I think that happens a little bit after the page loads), or maybe we should just ditch the idb entirely and load from the server every time, or maybe we should load the same way Google does (presumably idb + diff sync from a timestamp in the idb).

[simon-weber]

Thankfully Google stores the timestamp that the idb was retrieved with, so I can just diff update from that.