Remove CreateRelatedIssueService

app/services/create_related_issue_service.rb

-class CreateRelatedIssueService < BaseService
-  def initialize(issue, user, params)
-    @issue, @current_user, @params = issue, user, params.dup
-  end
-
-  def execute
-    if referenced_issues.blank?
-      return error('No Issue found for given reference', 401)
-    end
-
-    begin
-      create_related_issues!
-    rescue => exception
-      return error(exception.message, 401)
-    end
-
-    success(message: "#{issues_sentence(referenced_issues)} were successfully related")
-  end
-
-  private
-
-  def create_related_issues!
-    RelatedIssue.transaction do
-      referenced_issues.each do |referenced_issue|
-        RelatedIssue.create!(issue: @issue, related_issue: referenced_issue)
-      end
-    end
-  end
-
-  def referenced_issues
-    @referenced_issues ||= begin
-      issue_references = params[:issue_references]
-      text = issue_references.join(' ')
-
-      extractor = Gitlab::ReferenceExtractor.new(@issue.project, @current_user)
-      extractor.analyze(text)
-
-      extractor.issues
-    end
-  end
-
-  def issues_sentence(issues)
-    issues.map { |issue| issue.to_reference(@issue.project) }.sort.to_sentence
-  end
-end