Allow superusers to create standalone clusters from UI

[matthew-li]

In addition to the "primary" cluster (Savio for BRC, Lawrencium for LRC), our group also manages various "standalone" clusters purchased/owned by individual PIs/groups. Examples include ABC (BRC) and NANO (LRC).

Whereas the primary cluster is host to many projects (FCA/PCA projects, ICA projects, Condo projects, etc.), each standalone cluster has exactly one corresponding project, with the same name as the cluster (e.g., "abc" for ABC, "nano" for NANO).

Standalone clusters have thus far been created from hard-coded data in a management command: coldfront.core.utils.management.commands.add_accounting_defaults.

It would be preferable for superusers to be able to create these from the UI.

Create a new multi-part view:

• Forms:
  • The name of the cluster
  • The PI of the cluster
    • The requesting user is first prompted to choose an existing user. If the user doesn't exist, they'll leave it blank, and will then be prompted to provide information to create a new user. This is the same as the flow for a new project request.
  • The manager of the cluster
    • Same as for the PI.
• Back-end processing
  • Create a Resource object to represent the cluster (see the management command). The cluster name should be capitalized.
  • Create a corresponding Project for the cluster. Example code for this can be provided on request. The project name should be the cluster name in lowercase.

[matthew-li]

• It's possible there may be multiple PIs. We'll just ask for one PI, and we'll handle the others manually for now. A CLI (or UI) tool to add PIs to a project would be generally useful.
• Users should generally be added to the project from the UI, but in some cases, it may(?) be necessary to parse existing users from a passwd file. Some logic for doing this already exists.