feat(extensions): add toggle all checkbox to Installed tab

Small QoL addition.

While there is the option to disable all extensions with the radio buttons at the top, that only acts as an added flag and doesn't really change the state of the extensions in the UI.

An use case for this checkbox is to disable all extensions except for a few, which is important for debugging extensions.
You could do that before, but you'd have to uncheck and recheck every extension one by one.

javascript/extensions.js

@@ -72,3 +72,21 @@ function config_state_confirm_restore(_, config_state_name, config_restore_type)
     }
     return [confirmed, config_state_name, config_restore_type];
 }
+
+function toggle_all_extensions(event) {
+    gradioApp().querySelectorAll('#extensions .extension_toggle').forEach(function(checkbox_el) {
+        checkbox_el.checked = event.target.checked;
+    });
+}
+
+function toggle_extension() {
+    let all_extensions_toggled = true;
+    for (const checkbox_el of gradioApp().querySelectorAll('#extensions .extension_toggle')) {
+        if (!checkbox_el.checked) {
+            all_extensions_toggled = false;
+            break;
+        }
+    }
+
+    gradioApp().querySelector('#extensions .all_extensions_toggle').checked = all_extensions_toggled;
+}