Add identity common items for new functionality (#1027)

* moving common auth items to identity.ts and fixing UserRecord definitions

* fixing copyright year and exporting old artifacts

* adding in common files only

* breaking out parsing functions and adding a bunch of tests

* clean up & formatter

* adding jsdoc comments

* cleaning up update mask and adding more tests

* fixing projectId references

* changing classes to interfaces, adding in a key cache, and more tests

* formatter

* decoupling decode & verify

* added tests for setting the expiration time

* cleaning up var names

* adding in retry for key verification

* format

* address comments

* add package-lock

* change decoded JWT to decoded payload

Author: colerogers

package-lock.json

@@ -157,7 +157,8 @@
     "@types/express": "4.17.3",
     "cors": "^2.8.5",
     "express": "^4.17.1",
-    "lodash": "^4.17.14"
+    "lodash": "^4.17.14",
+    "node-fetch": "^2.6.7"
   },
   "devDependencies": {
     "@types/chai": "^4.1.7",
@@ -168,6 +169,7 @@
     "@types/mock-require": "^2.0.0",
     "@types/nock": "^10.0.3",
     "@types/node": "^8.10.50",
+    "@types/node-fetch": "^3.0.3",
     "@types/sinon": "^7.0.13",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",