[dvsim] Fixes to UNR and cov analysis flows
[dvsim] Fixes to UNR and cov analysis flows

- Set Cov analysis to use GUI mode by default
- Designate input directories for both flows

Signed-off-by: Srikrishna Iyer <2803d640feace36379942447842f26c7747b4dc3@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan