Review status change: user unable to edit review comment without switching to different and switching back

[whisperity]

If a user sets the review status to something and then wants to edit it, the only way to do so is by switching to a different review status and committing a dummy or empty message, then switching back to the intended review status and typing in (or pasting...) the edited message.

~~If #746 ever happens, this will create a bloat for the report's history.~~

Edit: This part above is fixed since, identity changes are not creating additional "system comment" records.

Suggestion: When the user opens the review status drop-down and selects the same value as the current one, the comment window should open with the current comment pre-loaded. The user types in the new text (use case is adding new information why something is false positive or intentional) and commits it. (This will only result in one action changing the database and one "system comment" for #746 later.) If the user doesn't want to edit, the ESC or close button will cancel the action.

[whisperity]

This was partially fixed, I believe. The review status change is only committed if the message differs.

However, the existing status still needs to be loaded from either the 🗯️ icon, or from the system comments.