Fix - Foam workspace update (live) (#497)

* improved delta logic in graph.js

fixes a bug that was due to using object.splice inside a forEach loop (sometimes stackoverflow is wrong - removing the element inside the loop will actually reduce the iterations and not all elements in the array will be visited!)

* various fixes to live update of workspace model + tests

* added tab size option in settings.json

.vscode/settings.json

@@ -21,5 +21,6 @@
   "editor.defaultFormatter": "esbenp.prettier-vscode",
   "prettier.requireConfig": true,
   "editor.formatOnSave": true,
+  "editor.tabSize": 2,
   "jest.debugCodeLens.showWhenTestStateIn": ["fail", "unknown", "pass"]
 }