[Commenting] - UI suggested features for usability

[zeigerpuppy]

The following are not bugs but desirable features to assist users in commenting:

1. allow adding a comment from viewer and view-only mode
   • this feature would be very useful for non-technical users so they can add comments from a rendered view
2. allow adding comment without selecting string
   • currently comment adding fails if the cursor is placed but no string is selected
   • in some cases, a user may want to comment by just selecting a cursor position
   • perhaps a single character could be auto-selected as the anchor