Pull in correct context; add xstate package

extensions/measurement-tracking/src/getContextModule.js

@@ -1,38 +1,18 @@
-import React, { useState } from 'react';
-import { ViewModelContext } from '@ohif/core';
-
-const HelloWorldContext = React.createContext({
-  message: 'HelloWorldContextTesting',
-  setMessage: () => {},
-});
-
-HelloWorldContext.displayName = 'HelloWorldContext';
-
-function HelloWorldContextProvider({ children }) {
-  const [message, setMessage] = useState('HelloWorldContextTesting');
-
-  return (
-    <HelloWorldContext.Provider
-      value={{
-        message,
-        setMessage,
-      }}
-    >
-      {children}
-    </HelloWorldContext.Provider>
-  );
-}
+import {
+  TrackedMeasurementsContext,
+  TrackedMeasurementsContextProvider,
+  useTrackedMeasurements,
+} from './contexts';
 
 function getContextModule() {
   return [
     {
-      name: 'HelloWorldContext',
-      context: HelloWorldContext,
-      provider: HelloWorldContextProvider,
+      name: 'TrackedMeasurementsContext',
+      context: TrackedMeasurementsContext,
+      provider: TrackedMeasurementsContextProvider,
     },
   ];
 }
 
-export { HelloWorldContext };
-
+export { useTrackedMeasurements };
 export default getContextModule;