Backport of Fix to not create a watch to Internal.ServiceDump when mesh gateway is not used into release/1.15.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #20168 to be assessed for backporting due to the inclusion of the label backport/1.15.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
you will see a blank no-op commit below. If at least one commit succeeded, you
will see the cherry-picked commits up to, not including, the commit where
the merge conflict occurred.

The person who merged in the original PR is:
@hashi-derek
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: unable to process merge commit: "9b7973ad2ccb06b623a64002ec483e92b7406090", automatic backport requires rebase workflow

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

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Description

This add a fix to properly verify the gateway mode before creating a watch specific to mesh gateways. This watch have a high performance cost and when mesh gateways are not used is not used.

This also adds an optimization to only return the nodes when watching the Internal.ServiceDump RPC to avoid unnecessary disco chain compilation. As watches in proxy config only need the nodes.

Testing & Reproduction steps

Added a test to create a set of services with mesh gateway mode default and expecting that this watch is not effective.

Links

PR Checklist

• updated test coverage
• appropriate backport labels added
• not a security concern

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Overview of commits

• b0ce20b - 3d4bde0 - b2c7724 - e7ab4d4 - d00d9c5 - b2db3d5 - 50fb45a - 7b41a61 - 2fa0e0a - 88849c9 - 4ac54f1 - 2a9dfc3 - 9b7973a

[github-team-consul-core-pr-approver]

Auto approved Consul Bot automated PR