Add types and comments to make combined image+text decluttering clearer

src/ol/render/canvas.js

@@ -77,6 +77,10 @@ import {toString} from '../transform.js';
  * @property {!Object<string, StrokeState>} [strokeStates] The stroke states (decluttering).
  */
 
+/**
+ * @typedef {Object<number, import("./canvas/Executor.js").ReplayImageOrLabelArgs>} DeclutterImageWithText
+ */
+
 /**
  * @const
  * @type {string}