erp5_crm: show attachments having filename only in EmailDocument_viewAttachmentListRenderer.

also add rel="noopener noreferrer" for security.
5 jobs for for_testrunner_1
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

running ERP5.UnitTest-Master

34324:47:54

running ERP5.UnitTest-Master.Medusa

34324:38:04

running SlapOS.Eggs.UnitTest-Master.Python2

34324:39:52

passed SlapOS.Eggs.UnitTest-Master.Python3