FI-584: Validate CapabilityStatement

[Jammjammjamm]

This branch makes test C-02 validate the server's CapabilityStatement. Before, it just checked that a CapabilityStatement model could be populated from the server's response without actually validating the contents of the CapabilityStatement.

Submitter:

• This pull request describes why these changes were made
• Internal ticket for this PR: https://oncprojectracking.healthit.gov/support/browse/FI-584
• Internal ticket links to this PR
• Internal ticket is properly labeled (Community/Program)
• Internal ticket has a justification for its Community/Program label
• Code diff has been reviewed for extraneous/missing code
• Tests are included and test edge cases
• Tests/code quality metrics have been run locally and pass

Reviewer 1:

Name:

• Code is maintainable and reusable, reuses existing code and infrastructure
  where appropriate, and accomplishes the task's purpose
• The tests appropriately test the new code, including edge cases
• You have tried to break the code

Reviewer 2:

Name:

• Code is maintainable and reusable, reuses existing code and infrastructure
  where appropriate, and accomplishes the task's purpose
• The tests appropriately test the new code, including edge cases
• You have tried to break the code

[okeefm]

Tested with an external CapabilityStatement; worked for me.