fix(MeshTrafficPermission): support permissive mtls (backport of #8171)

[kumahq]

Automatic cherry-pick of #8171 for branch release-2.1

Generated by action

cherry-picked commit 0e0489f
⚠️ ⚠️ ⚠️ Conflicts happened when cherry-picking! ⚠️ ⚠️ ⚠️

On branch release-2.1
Your branch is up to date with 'origin/release-2.1'.

You are currently cherry-picking commit 0e0489feb.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   pkg/plugins/policies/meshtrafficpermission/plugin/v1alpha1/plugin.go
	modified:   pkg/plugins/policies/meshtrafficpermission/plugin/v1alpha1/testdata/apply.golden.yaml
	modified:   pkg/test/resources/builders/mesh_builder.go
	modified:   pkg/xds/generator/inbound_proxy_generator.go
	modified:   pkg/xds/generator/testdata/inbound-proxy/5-envoy-config.golden.yaml
	modified:   pkg/xds/generator/testdata/inbound-proxy/6-envoy-config.golden.yaml

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   pkg/plugins/policies/meshtrafficpermission/plugin/v1alpha1/plugin_test.go
	both modified:   test/e2e_env/universal/meshtrafficpermission/meshtrafficpermission.go

[jakubdyszkiewicz]

the test is flaky. It's not clear for me why

[slonka]

@jakubdyszkiewicz looks like this does not work for this release, can you look into this?

[jakubdyszkiewicz]

Closing for now as nobody ever asked about this in 2.1 and it seems to take a significant amount of work to make this work. If needed, we can reopen, work on it and release new patch of 2.1