Add StudyGroup to RemoteEvaluationMapping

app/models/remote_evaluation_mapping.rb

@@ -3,6 +3,7 @@ class RemoteEvaluationMapping < ApplicationRecord
   before_create :generate_token, unless: :validation_token?
   belongs_to :exercise
   belongs_to :user, polymorphic: true
+  belongs_to :study_group, optional: true
 
   def generate_token
     self.validation_token = SecureRandom.urlsafe_base64

app/models/study_group.rb

@@ -5,6 +5,7 @@ class StudyGroup < ApplicationRecord
   has_many :external_users, through: :study_group_memberships, source_type: 'ExternalUser', source: :user
   has_many :internal_users, through: :study_group_memberships, source_type: 'InternalUser', source: :user
   has_many :submissions, dependent: :nullify
+  has_many :remote_evaluation_mappings, dependent: :nullify
   belongs_to :consumer
 
   def users

app/models/user.rb

@@ -13,6 +13,7 @@ class User < ApplicationRecord
   has_many :user_proxy_exercise_exercises, as: :user
   has_many :user_exercise_interventions, as: :user
   has_many :interventions, through: :user_exercise_interventions
+  has_many :remote_evaluation_mappings, as: :user
   has_one :codeharbor_link, dependent: :destroy
   accepts_nested_attributes_for :user_proxy_exercise_exercises