pricing object as db table; general pricing object model added (and remo...

pricing object as db table; 
general pricing object model added (and removed asset model and tenant group);
team manager added; 
base usages moved to over 100 id and default other extra cost type added
exactly this class is named as PricingObjectModel with model at the end, hmm. Now there is no case where this field is null. Maybe write in code new comment similar to your comment from github? this is more clarify when "sure to nullable?"