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/system/src/utils/index.ts

@@ -3,3 +3,4 @@ export * from './edges';
 export * from './graph';
 export * from './general';
 export * from './marker';
+export * from './store';