Virtualization Management, installation status fix, follow-up

[torchiaf]

Is your feature request related to a problem? Please describe.

When installing an extension, the POST request returns immediately, even if the extension's package is not really available to be consumed by the UI.
As workaround, we implemented a polling in the Virtualization Management page for when installing Harvester, to request the extension's package until 200 is received, then the UI reloads the page and the extension is finally available.

Rancher is now providing new status fields to correctly track the extension's installation process: rancher/rancher#48099

Describe the solution you'd like

We should remove the polling from Virt page and use the new status fields to check the installation process.

Describe alternatives you've considered

Additional context