Rescue errors when emitting Snowplow events

What does this MR do?

When a Snowplow event is emitted (by calling Gitlab::Tracking.event), we want to ensure that we do not raise any errors, even when the event is bad/invalid (eg. missing category). We can do this by taking inspiration from the Snowplow API helper and rescuing errors that occur within Gitlab::Tracking.event. A log message is also written to keep track of errors. Example of such an error affecting production: #238229 (closed).

!56267 (merged) removes the API helper in favour of calling Gitlab::Tracking.event directly, so this MR is also in preparation for that.

Does this MR meet the acceptance criteria?

Conformity

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  • I have included a changelog entry.
  • I have not included a changelog entry because no user-facing changes.
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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
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Security

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