Declutter multi geometries per geometry instead of per feature

src/ol/render/canvas.js

@@ -62,7 +62,6 @@ import LabelCache from './canvas/LabelCache.js';
  * @property {Array<number>} [padding]
  */
 
-
 /**
  * Container for decluttered replay instructions that need to be rendered or
  * omitted together, i.e. when styles render both an image and text, or for the
@@ -76,6 +75,12 @@ import LabelCache from './canvas/LabelCache.js';
  */
 
 
+/**
+ * Declutter groups for support of multi geometries.
+ * @typedef {Array<DeclutterGroup>} DeclutterGroups
+ */
+
+
 /**
  * @const
  * @type {string}