[idea] Rename the selected workspace, tab, or pane from the session navigator

[anagrius]

When the session navigator is open (prefix+g), I already have the workspace, tab, or pane selected, but I cannot act on it from there. I have to close the navigator and use the prefix bindings or a sidebar/tab right-click instead.

Rename is the one that matters most. I open the navigator to get an overview of the session. If I cannot name things from that list, it fills up with default labels — 1, 2, pane 1 — and equally named tabs and panes stop being distinguishable. The overview is the reason the navigator exists.

Close would be useful there too, and probably other high-level operations later. The selected row is already the thing I want to change.

A local implementation of rename is on this branch: https://github.com/anagrius/herdr/tree/feat/navigator-rename