Introduce apiVersion into zarf.yaml schema

[AustinAbro321]

Is your feature request related to a problem? Please describe.

Soon we will implement the changes in #2600, we would like to first create an apiVersion field for the current schema and version it to v1alpha1, so that it can be locked into place and exist as something that can be pulled. This will also make it easy for us to make a v1beta1 schema that will test out the changes proposed in #2600.