[ENH] - Implement JupyterHub 5.x sharing APIs in the hub client

[aktech]

Feature description

Implement JupyterHub 5.x sharing APIs in the hub client:

Use JupyterHub 5.x APIs to share an app, implement the following functionality in the HubClient:

• Grant shared access to a list of users and/or a list of groups API Docs
• Revoke all shared access to a given server API Docs
• Fetch shared apps (servers) for a given user API Docs

Value and/or benefit

This will help us move one step forward towards implementing app sharing, see #11

Anything else?

No response

[aktech]

We should add share_with key in the user_options in the request payload to create/edit server/app API know to let API know with whom to share the server/app with:

{
  "servername": "app name",
  "user_options": {
    "jhub_app": true,
    "name": "app name",
    "display_name": "app name",
    "description": "",
    "framework": "panel",
    "thumbnail": "",
    "filepath": "",
    "conda_env": "",
    "env": null,
    "custom_command": "",
    "profile": "",
    "public": false,
    "share_with": {
      "users": [],
      "groups": []
    }
  }
}

[aktech]

Complete in #224