Create API view to fetch other user's completed challenges

[HuxleyBerry]

The view should take the username of a user as input and do the following things:

• Return the users first name, last name, avatar, bio, and number of points
• Calculate whether the logged in user (call them Y) has permission to view the completed challenges of this user (call them X)
  • If X has their visibility set to "BlueCrew Only", then Y can view X's completed challenges if and only if Y is staff
  • If X has their visibility set to "Friends Only", then Y can view X's completed challenges if and only if Y is staff or X is friends with Y
  • If X has their visibility set to "Public", then Y can always view X's completed challenge
• If Y does indeed have permission to view X's completed challenges, then for each challenge completed by X (i.e. each instance of the TileInteraction model which is linked to X), the following information should be returned:
  • The name of the challenge
  • The description of the challenge
  • The type of the challenge (connect/understand/act)
  • How many points the challenge was worth
  • The image X uploaded for the challenge
  • The date X started the challenge
  • The date X finished the challenge

The trickiest thing here is probably sending the image files to the frontend. I'm not sure of the details, but it could end up being hard to send multiple images together with json data. If so, an alternate option is for this view to not return the images, and instead have a separate view which would return a single image which would be called when the user clicks a button.

[github-actions]

Branch issue-118-Create_API_view_to_fetch_other_user_s_completed_challenges created!