Merge pull request #1088 from inthause/APIWeb

Some fixes
Fix credit notes amount in CartDataComposer and OrderDataComposer (there is no tax notion here).
Add notifications on product returns + refactor commerce notifications + fixes.
Update short cart, adding content summary.
Merge pull request #1087 from intportg/APIWeb

Notifications on product returns + refactoring and fixes
Merge pull request #1089 from inthause/APIWeb

Fix order process payment step
Update order process