Added missing PowerDNS configuration setup that was present in v2.4.4:
- Added installPowerDNSConfigurations() method to properly copy and configure pdns.conf
- Fixed PowerDNS installation to call configuration method after package installation
- Updated fixAndStartPowerDNS() to copy config template if missing
- Added proper MySQL password configuration for PowerDNS backend
- Added errno import for proper error handling
This fixes PowerDNS installation failures by ensuring the configuration file is properly created and configured with database credentials.