Support "rename label/context" action

[t7ko]

Suggested method -- right click in filter pane on the left, drop down menu with entry "rename", then dialog (or in-place editing, whichever easier).

Use case: I recently started using a flow where I create project name with numerical prefixes like 01, 02 etc, so they stay on top of projects list and I see them first when reviewing. Small problem is when such project is put on hold or lowered in priority, there is no easy way to "move it down" in the list, as there is no "rename" feature in jdotxt. I have to resort to text editors for such change,which is less convenient.

[t7ko]

Done - closing.