Spec Msf::Ui::Console::CommandDispatcher::Db

MSP-11622

Spec methods that `Msf::Ui::Console::CommandDispatcher::Db` responds to in order to ensure methods aren't dropped when `Msf::Ui::Console::CommandDispatcher::Db` is broken up for MSP-11128

# Verification Steps

## specs
- [ ] `rake spec`
- [ ] VERIFY no failures
- [ ] VERIFY all public methods in `Msf::Ui::Console::CommandDispatcher::Db` have at a `respond_to` example.