Fix: Governance expiry warning should have proper year at all times

• handle governance expiry date back in 1969/1970
• handle expired governance
• fix auto-scroll to highlighted witness
• Undefined showing on witnesses page

Closes #36 (closed)

changed title from Closes #36 (closed) to Closes #36 (closed) - Governance expiry warning should have proper year at all times

changed title from Closes #36 - Governance expiry warning should have proper year at all times to Fix: Governance expiry warning should have proper year at all times

merged

mentioned in commit a0e267ad