Related keys for translated relations

Implement related keys for translated relations (like `source__translated__title`) and change content translation to index categories, by also indexing types whose translation is set in Localizer.

See merge request !1292
18 jobs for erp5-vifib
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

02:02:13

passed ERP5.PerformanceTest-Master

00:24:38

failed ERP5.UnitTest-Master

03:49:50

failed ERP5.UnitTest-Master.Medusa

02:50:44

passed SlapOS.Eggs.UnitTest-Master.Python2

00:08:19

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:07

failed ERP5.UnitTest-Master

01:43:32

failed ERP5.UnitTest-Master

06:06:00

failed ERP5.UnitTest-Master

02:08:06

passed SlapOS.Eggs.UnitTest-Master.Python2

00:33:59

passed SlapOS.Eggs.UnitTest-Master.Python2

00:10:44

passed SlapOS.Eggs.UnitTest-Master.Python2

00:32:07

passed SlapOS.Eggs.UnitTest-Master.Python2

00:18:14

passed SlapOS.Eggs.UnitTest-Master.Python3

00:18:03

passed SlapOS.Eggs.UnitTest-Master.Python3

00:36:57

passed SlapOS.Eggs.UnitTest-Master.Python3

00:17:18

passed SlapOS.Eggs.UnitTest-Master.Python3

00:11:05

passed SlapOS.Eggs.UnitTest-Master.Python3