chore: added warnings

Warning 1: if elements have the same name, show a warning.
Warning 2: if a goal/triggerNode has no/empty plan, show a warning.
Warning 3: if (non-phase) elements start with or are a number,
    show a warning.

src/pages/VisProgPage/visualProgrammingUI/components/EditorWarnings.tsx

@@ -23,6 +23,8 @@ export type WarningType =
   | 'PLAN_IS_UNDEFINED'
   | 'INCOMPLETE_PROGRAM'
   | 'NOT_CONNECTED_TO_PROGRAM'
+  | 'ELEMENT_STARTS_WITH_NUMBER' //(non-phase)elements are not allowed to be or start with a number
+  | 'DUPLICATE_ELEMENT_NAME' // elements are not allowed to have the same name as another element
   | string
 
 export type WarningSeverity =