erp5_core: improve activity viewer look

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5 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Master

05:11:13

passed SlapOS.Eggs.UnitTest-Master.Python2

00:22:40

passed SlapOS.Eggs.UnitTest-Master.Python3

00:14:11

passed SlapOS.Eggs.UnitTest-Master.Python2

00:22:54

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:27