nozzle/test: use gstruct, ignore time comparisons
nozzle/test: use gstruct, ignore time comparisons

gomega.Equal uses deepequal to compare time values. The code we're
checking goes from time.Time -> int64 -> time.Time. The time is
'equivalent' but the internals of the time struct are different.

- Added one check of the time to ensure the expected conversion path
  converts (comparing directly with unix timestamp)
- Updated matchers to use gstruct.MatchAllElements/MatchAllFields so we
  can Ignore() the EventTime. Also gives much better error messages.

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