fix: duplicate setState on vue flow mount

# What's changed?

* Set props on watcher initialization, so we avoid duplicate setStates (from composable and watchers)
* Fix pausable watchers not starting up
* Flush watchers on post

package/src/store/state.ts

@@ -38,6 +38,8 @@ const isDef = <T>(val: T): val is NonNullable<T> => typeof val !== 'undefined'
 const defaultState = (): State => ({
   nodes: [],
   edges: [],
+  nodeTypes: {},
+  edgeTypes: {},
 
   initialized: false,
   instance: null,