Provide a meaningful HAR file name

[Llandy3d]

When creating an HAR file the name that it's given is the date ex. 2024-10-31_15-13-44.har

Given that now we ask for an input URL before starting the recording we can provide a more meaningful name for the generated recording that includes the hostname when the input is available, otherwise we can continue with the date as name.
Ex. grafana.com-2024-10-31_15-13-44.har