Backport of GH-3406 - Only error for config entries from different datacenters when the config entries are different into release/1.3.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #3873 to be assessed for backporting due to the inclusion of the label backport/1.3.x.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
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The person who merged in the original PR is:
@jmurret
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

merge conflict error: POST https://api.github.com/repos/hashicorp/consul-k8s/merges: 409 Merge conflict []

The below text is copied from the body of the original PR.

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Fixes #3406

Changes proposed in this PR

How I've tested this PR

How I expect reviewers to test this PR

Checklist

• Tests added
• CHANGELOG entry added

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Overview of commits

• 0314f38 - 0077669 - 4f1b56d - d25f320

[hashicorp-cla-app]

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