sway: support workspace rename events

[quietvoid]

Simple enough to propagate the event of the rename.
However I'm not sure how to fix the order on rename, it doesn't seem to work if I just add

if self.sort == SortOrder::Alphanumeric {
    reorder_workspaces(&container);
}

[quietvoid]

It seems the ordering relies on widget_name while we're only changing the label.
Not sure which should be done of:

• Also changing widget_name and reorder
• Reorder based on label

My workspaces are all numbers so both would work, but maybe there's an edge case with named workspaces.

[JakeStanger]

Hm, I can't think why it would need to be tied to the widget name. Sorting by label instead should be fine.

[quietvoid]

Here we go. The reorder prioritizes the label if the widget is indeed a button, otherwise still uses the widget name.
I'm not too sure what other widgets are present in the container and if this could have a negative effect.
I think the workspace box is all buttons but I may be wrong.

[JakeStanger]

Thanks, LGTM. Everything in the container should always be a button, and should always have a label, but having the fallback is definitely good.