Merge pull request #1083 from intportg/APIWeb

Product returns + misc enhancements and fixes.
Add new 'Rbs_Price_UserGroup' document and implement price targetId.
Update product template twig structure
Merge pull request #1084 from inthause/APIWeb

Add new 'Rbs_Price_UserGroup' document and implement price targetId.
Refactor order process frontoffice code to reuse parts of it in return process.
Add new print template in common theme for pages dedicated to print.
Add return sheet rendering.
Clean up and code formatting.