[Notes] Small fixes and tweaks

[scambier]

I'm using this issue to log small pain points or quick-win tweaks that should be easily solved

• Show a notification "clear your cache" when several errors appear in a row
• Reduce the scoring of tokens that are only numbers and fewer than 4 chars? Make that as an option?
• It seems frontmatter properties aren't correctly indexed, e.g. a note containing the property keyword with the value foo bar won't appear in results when searching only foo
  • it was a bug in the embeds