Handle "Boot firmware" (BIOS or UEFI) when importing or exporting a VM (OVA)

[AtaxyaNetwork]

Is your feature request related to a problem? Please describe.
I was playing with a Cisco appliance, shipped in the .ova format. While the import was successful, the VMs did not start, because the "Boot firmware" was in "BIOS" and not in "UEFI" mode.
When I searched in the .ovf file (extracted from the .ova file), I saw this line:

<vmw:Config ovf:required="false" vmw:key="firmware" vmw:value="efi" />

To confirm my theory, I created a UEFI VM, and exported it, and I saw that the UEFI parameter is missing, as the exporting tool does not take account of this parameter.

Describe the solution you'd like
I would like XO to handle this line, so the VM is directly in "UEFI" mode after importing. With that, the users will not be confused to why their VM is not booting.

Describe alternatives you've considered
Maybe a way to change the "Boot firmware" in the OVA menu before importing (see image), but ideally it's should be automatic

Additional context
Thank you for your hard work ! 🚀