Add openbao proxy

Related to: gitlab#494888

What does this merge request do and why?

We have to start OpenBao behind the proxy by default - sample proxy confirugartion - gitlab!162431 (merged)

How to set up and validate locally

You can configure the OpenBao to run locally in GDK.

To configure:

1. Set the BAO_ADDR variable in your environment

   export BAO_ADDR='http://gdk.test:8200'

1. Run gdk config set openbao.enabled true.
2. Run gdk config set openbao_proxy.enabled true.
3. Run gdk reconfigure.
4. Run rake openbao/config.hcl to create a configuration file
5. Run openbao/proxy_config.hcl to create a proxy configuration file
6. Run gdk start openbao.
7. Run gdk bao configure to unseal the vault

=> "✅ OpenBao has been unsealed successfully"
=> "The root token is: s.xxxxxxxxxxxxxxx"

1. Set the BAO_TOKEN variable in your environment to use bao CLI. Run export BAO_TOKEN=s.xxxxxxxx
2. Run bao auth enable approle
3. Run bao write auth/approle/role/project_secret_engines_manager token_policies=manage_projects_secret_engines
4. Run bao read -field=role_id auth/approle/role/project_secret_engines_manager/role-id \> openbao/roleid
5. Run bao write -field=wrapping_token -f -wrap-ttl=1h auth/approle/role/project_secret_engines_manager/secret-id > openbao/secretid
6. Run OpenBaoProxy with gdk start openbao-proxy

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.