feat: associate task icon with workspaces (#20834)

## Problem

Workspaces associated with tasks were not visually distinguishable in
the workspaces list view. Additionally, the list workspaces endpoint was
not returning the `task_id` field.

<img width="2784" height="864" alt="Screenshot 2025-11-20 at 10 32 22"
src="https://github.com/user-attachments/assets/60704f16-3c66-4553-9215-f10654998a38"
/>

## Changes

- Fix `ConvertWorkspaceRows` to include `task_id` in the list workspaces
endpoint response
- Add "Task" icon to the workspace list view for workspaces associated
with tasks
- Add test to verify `task_id` is correctly returned by the list
workspaces endpoint
- Add Storybook story to showcase the Task icon in the workspace list

Closes https://github.com/coder/coder/issues/20802

coderd/database/modelmethods.go

@@ -662,6 +662,7 @@ func ConvertWorkspaceRows(rows []GetWorkspacesRow) []Workspace {
 			TemplateIcon:            r.TemplateIcon,
 			TemplateDescription:     r.TemplateDescription,
 			NextStartAt:             r.NextStartAt,
+			TaskID:                  r.TaskID,
 		}
 	}