Add Ingress configuration to GitLab resource v2alpha1

What does this MR do?

• Support setting the Ingress class name.
• Render NGINX annotations to the application server ingress.

Relates #30 (closed)

Changelog: added

Author's Checklist

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Ensure a release milestone is set.
• MR title and description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• MR has a green pipeline on GitLab.com.
• When ready for review, MR is labeled workflowready for review per the MR workflow.

Expected

• Test plan indicating conditions for success has been posted and passes.
• Documentation is created or updated.
• Tests are added.

Related issues

Closes #30 (closed)