Deno Subhosting: create organizations through API

### What problem are you trying to solve?

I have a PoC for Deno Subhosting and I found the need of creating organizations programmatically. I'd like to take advantage of having my potential clients isolated per organizations instead of projects. Currently, there is no way to create organizations through API. Are there any limitations to create organizations on demand?

### Describe the solution you'd like

Be able to create create organizations through API

### Describe alternatives you've considered

Using projects as main entity to isolate clients, but I find it insufficient.

### Documentation, Adoption, Migration Strategy

_No response_

No file, test, or entry point is named in the issue. Start by reviewing the existing Deno Subhosting API and its project model, then establish the supported organization-creation behavior and how success will be verified.

Written by the indexing model from the issue text.