More Manifest Version 3 related fixes.

We've recently had to update the extension to Manifest Version 3 that required us to completely rewrite the way sync works and expectedly a bugs appearing.
They are our top priority to fix so let us know if you run into any issues:

Fixes:

• Fix Memex interfering with Notion's editor when using Enter, Arrowkeys, escape and backspace

• Fix Popup slow loading after Service Worker shutdown

• Fix Google Login not working after MV3 updates, temporarily removed Twitter login because of other issues still to be identified.

• Fix UI slowdown (probably noticable on less powerful devices) caused by unecessary string serialisation

• Fix editor H1 and H2 sizes, and UX of using ## to write a H2 which was interfering with new # autocomplete

• UI fix with the template editor where it would be slightly transparent without the blur

• Fix image translation in text exports