- drop branches.utcDateCreated - not used for anything
- drop options.utcDateCreated - not used for anything
- isDeleted = 0 by default
- rename openTabs to openNoteContexts
- migrate black theme to dark theme
- unify readOnly handling to a single attribute:
  * readOnly - like now
  * readOnly=auto - like without readOnly (used to override inherited readOnly)
  * readOnly=never - like autoReadOnlyDisabled
- remove focusOnAttributesKeyboardShortcut
- rename white theme to "light" theme (it's not completely white and matches well to dark theme)