Error during operational intent details validation breaking tests

[StevenPG]

Describe the bug
When executing the tests and erroneously providing an operational intent response without volumes or off nominal volumes, the existing codebase attempts to retrieve the altitude_lower value from a volume that does not exist. This causes an exception.

This error keeps a developer from determining the real issue upstream (why the volumes are empty, for example) and requires manual cleanup of the test data before a test can be re-run.

To reproduce
Provide a OperationalIntent response that does not include volumes or off_nominal volumes, e.g. from the test report:

...
"elapsed_s": 0.376861,
"reported": "2024-12-04T17:15:31.327490Z",
"json": {
    "operational_intent": {
        "reference": {
            "id": "56ed11c9-63bc-4d2c-8fe6-189ea991fb53",
            "manager": "77e62cfb-d5f2-4c28-9baf-afbc6944b515",
            "version": 1,
            "ovn": ".T7Y14cSfGy-dZ8Q5cuTlYzXdaVEWG8iU7opU8VSZN0_",
            "time_start": {
                "value": "2024-12-04T17:15:13.547Z",
                "format": "RFC3339"
            },
            "time_end": {
                "value": "2024-12-04T18:00:14.547Z",
                "format": "RFC3339"
            },
            "uss_base_url": "https://myUss.com",
            "uss_availability": "Normal",
            "subscription_id": "7caaa804-28ed-4866-bb13-3b2427e239a3",
            "state": "Accepted"
        },
        "details": {
            "volumes": [],
            "off_nominal_volumes": [],
            "priority": 0
        }
    }
},
"body": null
},
"query_type": "astm.f3548.v21.uss.getOperationalIntentDetails",
"participant_id": "uss1_core"
...

Difference from expected behavior
Providing this response results in an error rather than an expected validation and failure.

Traceback (most recent call last):
    File "/app/monitoring/uss_qualifier/suites/suite.py", line 158, in _run_test_scenario
      scenario.run(context)
    File "/app/monitoring/uss_qualifier/scenarios/astm/utm/nominal_planning/conflict_equal_priority_not_permitted/conflict_equal_priority_not_permitted.py", line 228, in run
      flight_1_oi_ref = self._attempt_modify_planned_flight_conflict()
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/app/monitoring/uss_qualifier/scenarios/astm/utm/nominal_planning/conflict_equal_priority_not_permitted/conflict_equal_priority_not_permitted.py", line 353, in _attempt_modify_planned_flight_conflict
      flight_1_oi_ref = validator.expect_shared(
                        ^^^^^^^^^^^^^^^^^^^^^^^^
    File "/app/monitoring/uss_qualifier/scenarios/astm/utm/test_steps.py", line 217, in expect_shared
      self._check_op_intent_details(flight_info, oi_ref)
    File "/app/monitoring/uss_qualifier/scenarios/astm/utm/test_steps.py", line 434, in _check_op_intent_details
      error_text = validate_op_intent_details(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/app/monitoring/uss_qualifier/scenarios/astm/utm/evaluation.py", line 32, in validate_op_intent_details
      resp_alts = vol4c.meter_altitude_bounds
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/app/monitoring/monitorlib/geotemporal.py", line 366, in meter_altitude_bounds
      alt_lo = min(
               ^^^^
  ValueError: min() iterable argument is empty

Possible solution
A solution is simply to check for the length of volume responses in evaluation.py.

I will link the PR here: #856