Refactor/vanilla store utils (#3138)

* feat(stores): use vanilla store utils

* fix(store-utils): keep dimensions if possible

* feat(utils): add nodeDimension and panBy utils

* fix(svelte): use correct updateDim func

* refactor(react): cleanup store

* chore(tests): use new imports

packages/react/src/store/initialState.ts

@@ -40,7 +40,7 @@ const initialState: ReactFlowStore = {
   elementsSelectable: true,
   elevateNodesOnSelect: true,
   fitViewOnInit: false,
-  fitViewOnInitDone: false,
+  fitViewDone: false,
   fitViewOnInitOptions: undefined,
   selectNodesOnDrag: true,