Add pricing from deckbrew.com (refs #147)

* the previous PriceUpdater class has become abstract
* BLPPriceUpdater inherits the old code for blacklotusproject.com
* DBPriceUpdater is a new implementation for deckbrew.com
* add a setting to choose between the two
Test with split cards, AEther cards, question elemental, etc. Check `CardInfo::getCorrectedName()`