Add array body assertions to Emberfall ISSO CFACTS tests

[danielbowne]

Once aquia-inc/emberfall#36 is fixed and we upgrade, we can add proper body assertions to the ISSO CFACTS list test.

Currently skipped with a comment in backend/emberfall_tests.yml because Emberfall panics on []interface{} comparison.

What to add back:

  - url: http://localhost:8080/api/v1/cfactssystems
    method: GET
    headers:
      <<: *issoHeaders
    expect:
      status: 200
      headers:
        content-type: "application/json"
      body:
        json:
          data:
            - fisma_uuid: "E1D00198-36D4-4EAB-8C00-501E1D000999"
              fisma_acronym: "SLD-GEN"

This validates that the ISSO join filter actually returns the correct assigned system, not just a 200 with an empty array.

Also update the Makefile when upgrading Emberfall — the --config flag was renamed to --tests on main.

Blocked by: aquia-inc/emberfall#36 (PR #48 submitted)