Adds a per-workspace app-icon taskbar (Workspace class) to the
niri/workspaces module. Rebased onto master: integrated with the
existing window-rewrite feature so the {windows} and {total} format
replacements continue to work alongside the new taskbar.
Adds format-window-separator, window-rewrite and window-rewrite-default
options plus the {windows} format replacement to the niri/workspaces
module (rebased onto master; coexists with ignore-workspaces).
sewaustav