Add plugin user settings (#25517)

* Add plugin user settings

* Feedback and UI improvements

* Extract the plugin configuration instead of just validating it

* Fix lint

* Fix lint

* Divide between settings and sections

* i18n-extract

* Adjust icon location

* Add tests

* Improve documentation

* Force plugin id

* Fix test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/plugins/registry.ts

@@ -1225,4 +1225,22 @@ export default class PluginRegistry {
 
         return id;
     });
+
+    // Register a schema for user settings. This will show in the user settings modals
+    // and all values will be stored in the preferences with cateogry pp_${pluginId} and
+    // the name of the setting.
+    //
+    // The settings definition can be found in /src/types/plugins/user_settings.ts
+    //
+    // Malformed settings will be filtered out.
+    registerUserSettings = reArg(['setting'], ({setting}) => {
+        const data = {
+            pluginId: this.id,
+            setting,
+        };
+        store.dispatch({
+            type: ActionTypes.RECEIVED_PLUGIN_USER_SETTINGS,
+            data,
+        });
+    });
 }