Editing an oVirt compute resource allows changing the type, which is unsupported
Description of problem:
When editing compute resources of certain types (e.g. EC2 and oVirt), the form allows the user to change the CR type to another. This is unsupported on existing CRs as VM UUIDs will change and CR attributes don't get updated properly. Some CR types (e.g. libvirt) correctly have it disabled. This option should be disabled consistently.
Steps to Reproduce:
1. More>Provisioning>Compute Resources, create a new oVirt compute resource
2. Edit the existing compute resource
3. Check if the type can be changed to another (e.g. EC2)
Type dropdown menu is not disabled, allows changing it (perhaps with an error on save).
Type dropdown is greyed out and disabled.
The dropdown is disabled based on "f.object.uuid.present?", however not all CR types have UUIDs. It should probably be .new_record?.