CVC Check for electrical rules at block level, caravel and user project level

[azwefabless]

At the moment the CVC Check is being run only at the top level in th m-bailey check set. This is very late to discover an issue with a user project or a caravel block level design issue. We should nehanceth flow to run cvc much earlier and at each hierarchy and integration level until tapeout.

[marwaneltoukhy]

This is currently done by Mitch using his custom script. This script will be integrated into caravel_signoff scripts.