Description of problem:
Template validator fails on spec.domain.memory.guest values

Version-Release number of selected component (if applicable):
common templates version v0.26

How reproducible:
100%

Steps to Reproduce:
1.Try to create a VM from any common template of ver 0.26
2.
3.

Actual results:
fails to create a VM
validator show error
Error "This VM requires more memory.: mismatching type: , not int or resource.Quantity" for field ".spec.domain.memory.guest".

Expected results:
VM created successfully

Additional info:
Seems like like current template validator can't parse G,Gi,M,Mi,etc strings into integers (like with spec.domain.resources.requests.memory)

Gives error when setting memory.guest to 1.5Gi
vm.kubevirt.io/validations: |
      [
        {
          "name": "minimal-required-memory",
          "path": "jsonpath::.spec.domain.memory.guest",
          "rule": "integer",
          "message": "This VM requires more memory.",
          "min": 1610612736
        }

Validates resources.requests.memory value of 1.5Gi
vm.kubevirt.io/validations: |
      [
        {
          "name": "minimal-required-memory",
          "path": "jsonpath::.spec.domain.resources.requests.memory",
          "rule": "integer",
          "message": "This VM requires more memory.",
          "min": 1610612736
        }
      ]
      ]