Move and refactor method from follow to user model to get user interests. Add specification to check the discard of duplicate interests.

app/controllers/users_controller.rb

@@ -7,7 +7,7 @@ class UsersController < ApplicationController
 
   def show
     load_filtered_activity if valid_access?
-    load_interest if valid_interest_access?
+    load_interests if valid_interests_access?
   end
 
   private
@@ -63,15 +63,15 @@ class UsersController < ApplicationController
       @budget_investments = Budget::Investment.where(author_id: @user.id).order(created_at: :desc).page(params[:page])
     end
 
-    def load_interest
-      @interests = Follow.interests_by(@user)
+    def load_interests
+      @user.interests
     end
 
     def valid_access?
       @user.public_activity || authorized_current_user?
     end
 
-    def valid_interest_access?
+    def valid_interests_access?
       @user.public_interests || authorized_current_user?
     end