Allow for adding users to a challenge

[jmgasper]

Expected behavior

On the Resources tab, we will replace the Edit and Back buttons in the header with Add.

The Add button will bring up a popup, allowing the user to:

1. Select a member, with autocompletion, the same way we do on the Assignee field on a task
2. Select a role from the list below:

• Reviewer
• Iterative Reviewer
• Observer
• Client Manager
• Primary Screener
• Final Reviewer
• Manager
• Copilot
• Checkpoint Screener
• Checkpoint Reviewer
• Specification Submitter
• Specification Reviewer

There should be Add and Cancel buttons on the popup. Cancel will just close the popup

Add will add the user with the selected role by POST to the resources API, similar to how we add copilots when a challenge is edited to select one:

https://api.topcoder-dev.com/v5/resources

{
  "challengeId":"123efaf7-fd1f-4e5b-8df5-ad6d9eed3479",
  "roleId":"cfe12b3f-2a24-4639-9d8b-ec86726f76bd",
  "memberHandle":"TCConnCopilot"
}

Security

Only users with copilot or manager on the challenge, or admin privileges globally should be allowed to use the Add button