Also make this the default when one doesn't have a title. This is important as now the filename is far more visible with the new standard view.
This is so that we can start configuring what the yaml metadata keys should be called, and not have them hardcoded. This also allows the note.created to be null. Earlier we were always setting it to some value. That's doesn't seem right.
We should just use the 'timezone' dart package and not handle this ourselves as we're probably fucking it up in other places. This fixes #42