Application Credential support

[Deydra71]

Jira: OSPRH-16630

Adds the end-to-end support for consuming Keystone ApplicationCredentials (AC) in the Neutron operator, enabling Neutrons pod to use AC-based authentication when available.

Depends-On: openstack-k8s-operators/keystone-operator#567

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Deydra71
Once this PR has been reviewed and has the lgtm label, please assign slawqo for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[softwarefactory-project-zuul]

Merge Failed.

This change or one of its cross-repo dependencies was unable to be automatically merged with the current state of its repository. Please rebase the change and upload a new patchset.
Warning:
Error merging github.com/openstack-k8s-operators/keystone-operator for 567,560a7f552956fc9c80fece28fc7e7b01b59c2274

[softwarefactory-project-zuul]

Build failed (check pipeline). Post recheck (without leading slash)
to rerun all jobs. Make sure the failure cause has been resolved before
you rerun jobs.

https://softwarefactory-project.io/zuul/t/rdoproject.org/buildset/63583318171d436e8d3f933d389783e8

❌ openstack-k8s-operators-content-provider FAILURE in 15m 02s
⚠️ neutron-operator-tempest-multinode SKIPPED Skipped due to failed job openstack-k8s-operators-content-provider