Run Schema validations after beforeSave #2672 (#2677)

* Adds test to repro #2672

* Run schema validation after beforeSave is run

* Makes authData part of base _User object

* exclude flaky pg test

src/Controllers/SchemaController.js

@@ -31,6 +31,7 @@ const defaultColumns = Object.freeze({
     "password":      {type:'String'},
     "email":         {type:'String'},
     "emailVerified": {type:'Boolean'},
+    "authData":      {type:'Object'}
   },
   // The additional default columns for the _Installation collection (in addition to DefaultCols)
   _Installation: {