Change the default webpage name (index.html -> index_{package name}.html) to avoid the automated opening of the webpage when opening the output directory in a browser

This is more a suggestion than a actual issue, but that would be helpful to allow browsing easily an output directory of UPV (and VetoPerf and Omicron). Currently, the output webpage is called index.html, which means that it is automatically displayed when browsing the web directory. If the name were different -- say index_{package name}.html -- the user (developer) could choose to either open the webpage, or browse the files/subdirectories. And it would be easy to change the web link in the DQR code, to display the webpage using its right (new) name among the DQR outputs.