Add an "urgent" property for clients and workspaces on Hyprland

[luwucoso]

Is your feature request related to a problem? Please describe.
i like that on waybar i can change the icon and color of the workspaces if one of it's clients are urgent and i can't find a way to get that in astal

Describe the solution you'd like
the Hyprland.Workspace and Hyprland.Client should have a property that can be bindable to for whatever we might want to use

Describe alternatives you've considered
not sure how to answer this, it's a hyprland IPC event so i'd need to make my own tool to watch the IPC for urgent workspaces. there isn't anything similar to it right now i think.

Additional context
nothing