Fixed page reload issue and date time picker render (#218)

* Fixed page reload issue and date time picker render

* Removed redundant imports

* Addressed blank page issue

[Notes]
Blank page observed after submitting metadata definition via the dataset popup, rootcause found to be incorrect React state assignment. I've removed the temporary fix that was added

* Updated package dependencies.

* for now cast datetime as just str; will revist later

Co-authored-by: Luigi Marini <lmarini@illinois.edu>
Co-authored-by: Chen Wang <cwang138@illinois.edu>

Author: 3 people

backend/app/models/metadata.py

@@ -31,8 +31,11 @@
     "str": str,
     "TextField": str,
     "bool": bool,
-    "date": datetime.date,
-    "time": datetime.time,
+    # TODO figure out how to parse "yyyymmdd hh:mm:ssssssz" into datetime object
+    # "date": datetime.date,
+    # "time": datetime.time,
+    "date": str,
+    "time": str,
     "dict": dict,  # TODO: does this work?
     "enum": str,  # TODO: need a way to validate enum,
     "tuple": tuple,