MongoDB: AddCollection on MongoDBDatabaseResource

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

I am trying to describe mongo collections in aspire to accurately reflect my infra.

### Describe the solution you'd like

Add an extension method for `IResourceBuilder` that will create the collection and make sure it was created successfully.
Enable other resources to wait for its creation.

### Additional context

I have an initial implementation that works, but needs some work on tests.