Pull in correct context; add xstate package

extensions/measurement-tracking/package.json

@@ -28,13 +28,14 @@
   },
   "peerDependencies": {
     "@ohif/core": "^0.50.0",
+    "dcmjs": "^0.12.4",
     "prop-types": "^15.6.2",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
-    "webpack": "^4.0.0",
-    "dcmjs": "^0.12.4"
+    "webpack": "^4.0.0"
   },
   "dependencies": {
-    "@babel/runtime": "7.7.6"
+    "@babel/runtime": "7.7.6",
+    "xstate": "^4.10.0"
   }
 }