Add returns management

[pfferrari]

What I did

• Added the returns listing and filtering page

• Added the return detail page

Once a return is in status `received` it won't show any trigger action. The `Restock` link will be visible if any restockable return_line_item is available.

• Added the restock form

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests).
• Make sure to add/update documentation regarding your changes.
• You are NOT deprecating/removing a feature.

[pfferrari]

@malessani I just updated staging version of returns app with updated app-elements library to provide Restocked on badge for return_line_items. I also added restocked line items in return summary.
I temporarily left on a side only the issue about removing the checkbox selector when a single return line item is selectable in the Restock InputCheckboxGroup.

[malessani]

For the moment I would avoid to change the InputCheckboxGroup. Let's decide later on this

[pfferrari]

@malessani I just updated both stg and prd environments of returns app to bring these latest fixes:

• visibility of destination stock location in list elements
• Restocked on badge based on updated helper method to have Restocked today in case and with the user timezone
• Reference visible in detail page only if effectively not empty