Refactor AddressBook server to be compatible with the reqres.in

Refactor AddressBook server to be compatible with the reqres.in, meaning:

• Rename AddressBook to Color List/Color Palette
• Rename Contacts into Users
• Change user schema fields to contain id, email, first name, last name, avatar link
• Add Color schema - id, name, color, pantone value (ignore year)
• Have the updated_at/created_at fields in the user and return them only when the update/create of the user happens
• Implement missing functionalities in the server:
  • List users, colors with pagination
  • GET single user, color
  • POST new user
  • PUT/PATCH user data
  • DELETE user
  • POST Register user (add existing user to new list of users with assigned passwords and grant 'access' to the modifying requests by returning token)
  • POST login (get token for already registered user)
  • GET user avatar
• Keep the prepopulated json list of colors and users in the assets and load them when starting the server
• PUT, PATCH, DELETE commands must expect valid token to be passed in the header to authorize the request