software/{kvm,theia}: use unevaluatedProperties for schema composition

This is based on example from https://json-schema.org/understanding-json-schema/reference/object#unevaluatedproperties
this approach allows extending a schema from another software type with
some extra properties while rejecting other properties on instances,
like it's done with additionalProperties: false.
Status Job ID Name Coverage
  External
passed Cloudooo.UnitTest-Master

00:11:41

passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

00:26:00

failed ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

15:02:27

failed ERP5.UnitTest-Zope4Py3-Py2

11:20:04

passed SlapOS.Eggs.UnitTest-Master.Python2

00:37:16

failed SlapOS.Eggs.UnitTest-Master.Python3

00:45:47

failed SlapOS.SoftwareReleases.IntegrationTest-Master

16:57:39

passed SlapOS.Theia.ResilienceTest-Master-ERP5

19:30:38

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster

00:38:14

passed SlapOS.Eggs.UnitTest-Master.Python2

00:37:51

passed SlapOS.Eggs.UnitTest-Master.Python2

00:25:32

passed SlapOS.Eggs.UnitTest-Master.Python3

00:41:31