Description of problem:
It should be possible to import an OVA directly to a template using the REST API.

Now it is possible to export a template to OVA, but not the opposite.

Version-Release number of selected component (if applicable):
ovirt-engine-4.4.5.11-0.1.el8ev.noarch

How reproducible:
Always

Steps to Reproduce:
1. Export a template to OVA:

# curl -v -k --request POST \
    --header 'Version: 4' \
    --header 'Accept: application/xml' \
    --header 'Content-Type: application/xml' \
    -d '
<action>
  <host>
    <name>host01.example.com</name>
  </host>
  <directory>/var/tmp</directory>
  <filename>export-test.ova</filename>
</action>' \
    -u 'admin@internal:PASSWORD' \
    https://rhvm.example.com/ovirt-engine/api/templates/e0923990-cdbf-41d3-b73a-969c05060681/export


2. Try to import it using a POST call to /ovirt-engine/api/externalvmimports

# curl -v -k --request POST \
    --header 'Version: 4' \
    --header 'Accept: application/xml' \
    --header 'Content-Type: application/xml' \
    -d '
<external_vm_import>
  <vm>
    <name>import-test</name>
  </vm>
  <cluster id="00000002-0002-0002-0002-000000000246" />
  <storage_domain id="6814fac1-2e9a-4ab3-bbfe-02a14c2049fe" />
  <name>RHEL8_3</name>
  <sparse>true</sparse>
  <provider>kvm</provider>
  <host>
    <name>host01.example.com</name>
  </host>
  <url>ova:///var/tmp/export-test.ova</url>
</external_vm_import>' \
    -u 'admin@internal:PASSWORD' \
    https://rhvm.example.com/ovirt-engine/api/externalvmimports


Actual results:
externalvmimports only works for VMs and you cannot specify to import it as a template.

Expected results:
Be able to import templates directly.

Additional info: