combobox: add compact mode, open state callbacks

src/routes/+page.svelte

@@ -148,6 +148,7 @@
 		/>
 
 		<Combobox label="Lazy combobox" placeholder="Choose..." options={[]} lazy />
+		<Combobox label="Compact combobox" placeholder="Choose..." options={[]} lazy compact />
 	</InputGroup>
 </div>