tests/e2e: dump checker type along with event body

[willfindlay]

We weren't dumping the checker type before which was making it difficult to discern which
checks were which in the dump. Add it to the dump here.

Signed-off-by: William Findlay [email protected]

[willfindlay]

Example JSON output after this change. Note that we now include checker type in the output.

[
  {
    "ProcessExecChecker": {
      "process": {
        "binary": {
          "operator": "suffix",
          "value": "curl"
        },
        "pod": {
          "namespace": {
            "operator": "full",
            "value": "skeleton"
          }
        }
      }
    }
  }
]