message id generation: hash only the event and not the uuid

[andrewloyola]

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🦋 Changeset detected

Latest commit: 445210d98e10c72282ec91f75463b5429bba7d96

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

| Name | Type | | ----------------------- | ----- | | @segment/analytics-next | Patch |

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[silesky]

@andrewloyola thanks for your contribution! Couple things:

1. Can we yarn uninstall the md5 dependency?
2. Can you run "yarn test" and fix any broken tests?

[silesky]

Closing in favor of #1045