Issue 610: Superusers can create standalone clusters from UI

[adeng27]

Majority code from @haudquaquam

Changes:

• Adds request wizard for creating standalone clusters. The form can be found at /project/new-standalone-cluster-request/ and a link to it can be found on the admin menu.
• Views in new_project_views/request_views.py
• Forms in new_project_forms/request_forms.py
• Templates under project/project_request/standalone_cluster folder
• The wizard asks for the name and description of the cluster -> an existing PI -> if no existing PI provided, a new PI's info -> an existing manager -> if no existing manager provided, a new manager's info -> a review-and-submit page.
• Back-end:
  • Creates a Resource object and capitalizes the given name for that object.
  • Creates a Project object and ProjectUsers using the logic from the projects create subcommand
    • Some of the projects create subcommand's logic has been refactored into projects.utils_.new_project_utils

Testing

• Manual testing wizard:
  • Navigate to /project/new-standalone-cluster-request/, a link to it is found on the admin menu as "Create Standalone Cluster."
  • Go through the cluster creation
  • To test new PI and/or manager creation, do not select a PI/manager from the dropdowns. The next page will then prompt you to enter user info.
  • After successful submission, go to admin dashboard. Check to see that new Project and Resource objects were created.