SSP-2460 Fixups from code review

Highlights:

  - Whitespace/formatting cleanup
  - Imports cleanup
  - License headers
  - Remove dead POJO properties
  - More consistent error message formatting in EA portlet
  - Move request/response wrapping/mocking into PersonAttributeService
  - Remove dead methods on PersonAttributeService
  - Greatly expanded and more specific error handling in
    LtiConsumerService/Impl
  - Remove dead LtiConsumerServiceImpl code
  - Remove unused response Maps from LtiConsumerController
  - Revise error messaging in LtiConsumerController
  - Remove /launch/auth handler in LtiConsumerController
  - Change LtiSspUserFieldNames option from school_id to schoolId
    (needs to be a uPortal attribute name, not SSP field name)