kvm: Increase default VM parameters to match nowadays requirement

KVM which defaults to 1024 RAM, 10 GB disk and 1 CPU is too small for nowadays
OS requirements, so to avoid confusions, increase the defaults.
24 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.Eggs.UnitTest-Master.Python2

00:10:04

passed SlapOS.Eggs.UnitTest-Master.Python3

00:10:21

passed SlapOS.SlapRunner.ResilienceTest-Master

00:22:10

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:27:22

passed SlapOS.SoftwareReleases.IntegrationTest-Master.Python2

06:21:58

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

06:00:06

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

13:13:34

passed SlapOS.Eggs.UnitTest-Master.Python2

00:09:13

passed SlapOS.Eggs.UnitTest-Master.Python2

00:12:02

passed SlapOS.Eggs.UnitTest-Master.Python2

00:09:51

passed SlapOS.Eggs.UnitTest-Master.Python2

00:31:58

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:42

passed SlapOS.Eggs.UnitTest-Master.Python3

00:09:23

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:55

passed SlapOS.Eggs.UnitTest-Master.Python3

00:15:12

passed SlapOS.SlapRunner.ResilienceTest-Master

00:21:56

passed SlapOS.SlapRunner.ResilienceTest-Master

00:21:29

passed SlapOS.SlapRunner.ResilienceTest-Master

00:21:22

passed SlapOS.SlapRunner.ResilienceTest-Master

00:21:57

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:23:02

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:22:57

passed SlapOS.SoftwareReleases.IntegrationTest-Master.Python2

05:44:44

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

04:53:32

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

12:09:13