Move EE-only API endpoints mount to separate file

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

ee/lib/ee/api/endpoints.rb

+# frozen_string_literal: true
+
+module EE
+  module API
+    module Endpoints
+      extend ActiveSupport::Concern
+
+      prepended do
+        mount ::EE::API::Boards
+        mount ::EE::API::GroupBoards
+
+        mount ::API::Unleash
+        mount ::API::EpicIssues
+        mount ::API::Epics
+        mount ::API::Geo
+        mount ::API::GeoNodes
+        mount ::API::IssueLinks
+        mount ::API::Ldap
+        mount ::API::LdapGroupLinks
+        mount ::API::License
+        mount ::API::ProjectMirror
+        mount ::API::ProjectPushRule
+        mount ::API::MavenPackages
+      end
+    end
+  end
+end

lib/api/api.rb

@@ -170,26 +170,10 @@ module API
     mount ::API::Version
     mount ::API::Wikis
 
-    ## EE-specific API V4 endpoints START
-    mount ::EE::API::Boards
-    mount ::EE::API::GroupBoards
-
-    mount ::API::Unleash
-    mount ::API::EpicIssues
-    mount ::API::Epics
-    mount ::API::Geo
-    mount ::API::GeoNodes
-    mount ::API::IssueLinks
-    mount ::API::Ldap
-    mount ::API::LdapGroupLinks
-    mount ::API::License
-    mount ::API::ProjectMirror
-    mount ::API::ProjectPushRule
-    mount ::API::MavenPackages
-    ## EE-specific API V4 endpoints END
-
     route :any, '*path' do
       error!('404 Not Found', 404)
     end
   end
 end
+
+API::API.prepend(::EE::API::Endpoints)