Include all adjustments in final shipment price

(Not solely promotions and taxes.) As per discussion in https://github.com/spree/spree/issues/5415

Fixes #5415
Fixes #5419

Conflicts:
	core/app/models/spree/shipment.rb
Fix broken specs from 4441fb42acfbf7ebf02a44c116f0d09d61c3b54f & c3a741c