Change auto-following admin-selected accounts, show in recommendations (#16078)

app/controllers/api/v1/suggestions_controller.rb

@@ -5,20 +5,20 @@ class Api::V1::SuggestionsController < Api::BaseController
 
   before_action -> { doorkeeper_authorize! :read }
   before_action :require_user!
-  before_action :set_accounts
 
   def index
-    render json: @accounts, each_serializer: REST::AccountSerializer
+    suggestions = suggestions_source.get(current_account, limit: limit_param(DEFAULT_ACCOUNTS_LIMIT))
+    render json: suggestions.map(&:account), each_serializer: REST::AccountSerializer
   end
 
   def destroy
-    PotentialFriendshipTracker.remove(current_account.id, params[:id])
+    suggestions_source.remove(current_account, params[:id])
     render_empty
   end
 
   private
 
-  def set_accounts
-    @accounts = PotentialFriendshipTracker.get(current_account, limit_param(DEFAULT_ACCOUNTS_LIMIT))
+  def suggestions_source
+    AccountSuggestions::PastInteractionsSource.new
   end
 end