Description of problem:
The error messages in the WebConsole when pushing to DataVolumes is not very descriptive and sometimes an error is not displayed at all.

Version-Release number of selected component (if applicable):
OpenShift Container Native Virtualization - 2.55
OpenShift Platform - Web Console 4.6.x

How reproducible:
Ensure that OpenShift Virtualisation is installed correctly and there is a StorageClass configured for automatic provisioning of the PVs required.

Steps to Reproduce:
1. Download the RHEL QCOW image
2. Attempt to upload the RHEL image using the following guide. Ensure that the PV size is set to 5Gi.
https://docs.openshift.com/container-platform/4.6/virt/virtual_machines/virtual_disks/virt-uploading-local-disk-images-web.html

Actual results:
The upload fails and the progress-bar stalls. Nothing is displayed to the Web-Console, however intermittently there will be a `Error 400` displayed but this does not always happen.

Expected results:
The upload fails and an error message is displayed providing further information about the issue.

Additional info:

Inspecting the network packets we can see that this is a 400 error with the following contents:
~~~
HTTP/1.1 400 Bad Request
Access-Control-Allow-Origin: *
Content-Length: 120
Content-Type: text/plain; charset=utf-8
Date: Tue, 04 May 2021 23:58:36 GMT
Vary: Origin
Set-Cookie: 20168e521efcc36db27fbf0d0d57e7b6=03de3928c7031ce5975a265610c72ee4; path=/; HttpOnly; Secure; SameSite=None
------
Saving stream failed: Virtual image size 10737418240 is larger than available size 5179580416. A larger PVC is required.
~~~