adds db calls for subscriptions

[tonytheleg]

What this PR does

Before this PR:

• Subscription data was only stored in cache and not cosmos

After this PR:

• Subscription data is put into Cosmos DB
• Subscription data can be fetched and updated
• Document types are combined into single documents.go

Jira: ARO-7410
Link to demo recording:

Special notes for your reviewer

Validation of all changes available in Jira comments (LINK

Checklist

This checklist is not enforcing, but it's a reminder of items that could be relevant to every PR.
Approvers are expected to review this list.

• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Deployment: The deployment process was considered and addressed if required
• Testing: New code requires new unit tests.
• Documentation: Is the documentation updated? Either in the doc located in focus area, in the README or in the code itself.
• Customers: Is this change affecting customers? Is the release plan considered?

[mjlshen]

/lgtm, non-blocking question

[mbarnes]

Noted an error handling bug that needs fixed, but I like this overall.

[tonytheleg]

Throwing this in draft as there is one other bit of logic i think needs updating and want to make sure its all tested.

[tonytheleg]

Updates validated as working in cluster.

Latest changes re-organize the error checking to at least check for errors right after a call, but explicitly checks for the ErrNotFound first and then checking for any other errors in the same check. This way we're not going through motions of creating docs only to find the next check fails. Felt like a more common and cleaner way to handle this. Let me know what you think @mbarnes @mjlshen

[mbarnes]

Couple more nits. Requested change is for the status code, the other comment is optional.

[tonytheleg]

Requested changes added

[github-actions]

Please rebase pull request.

[mbarnes]

Approved once the merge conflict is resolved.