Backport of Integration test for ext-authz Envoy extension into release/1.16.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #17980 to be assessed for backporting due to the inclusion of the label backport/1.16.

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The person who merged in the original PR is:
@cthain
This person should manually cherry-pick the original PR into a new backport PR,
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The below text is copied from the body of the original PR.

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Description

This PR introduces a consul-container integration test for the Envoy external authorization extension. The test:

• Spins up a single Consul DC with a static-server and static-client.
• Adds an OPA agent container that loads its Rego policies from a locally mounted testdata directory.
• Applys the builtin/ext-authz Envoy extension to the static-server via a service-defaults config entry.
• Verifies that requests are permitted or denied as expected, based on the Rego policy.

Testing & Reproduction steps

consul$ make test-compat-integ-setup
consul$ cd ./test/integration/consul-container && go test ./test/envoy_extensions/... && cd -

PR Checklist

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

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Overview of commits

• 6699b17 - c094df6 - d2203de - f0bbbbb

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

Auto approved Consul Bot automated PR