[JIRAALIGN-1586] API 2.0 : Endpoints are returning HTTP 400 BAD REQUEST

Issue Summary

API 2.0 endpoints are mistakenly returning the error message below when using a non-Super Admin user:

HTTP 400 BAD REQUEST 

Steps to Reproduce

1. By using a valid non-Super Admin token, make the following API v2 GET call (examples below):
   1. /rest/align/api/2/Themes
   2. /rest/align/api/2/Epics
   3. /rest/align/api/2/Capabilities
   4. /rest/align/api/2/Features

Expected Results

• Notice authentication works
• Notice status code HTTP 200 OK then work items are returned

Actual Results

• Notice no mention to authentication errors – assuming it worked due to previous results plus the lack of 401 error code.
• Notice HTTP 400 BAD REQUEST and variations of it.
• Splunk log:

{ [-]
  Level: Error
   MessageTemplate: Cannot find epics. Value cannot be null. (Parameter 'source')
   Properties: { [-]
     ActionId: 9ab9cbfb-1a44-445e-8ab9-d54703a57942
     ActionName: AgileCraft.Api.Controllers.EpicsController.Get (AgileCraft.Api)
     Build: 10.73.0.6051
     ParentId:
     Product: AgileCraft.Api
     RequestId: 8000d662-0000-d100-b63f-84710c7967bb
     RequestPath: /rest/align/api/2/Epics
     SourceContext: AgileCraft.Api.Controllers.EpicsController
     SpanId: |ebb1bc55-4f23ce828eaf354f.
     TraceId: ebb1bc55-4f23ce828eaf354f
   }
   RenderedMessage: Cannot find epics. Value cannot be null. (Parameter 'source')
   Timestamp: 2020-06-22T12:21:16.7043897-04:00
}

Workaround

Set the role of the API user (user the token is associated with) to Super Admin and results will return as expected.