Allow vendor/customer returns Actions only for suitable HUs

[metas-rc]

• Followup for https://github.com/metasfresh/metasfresh-webui-api/issues/396

Is this a bug or feature request?

• Enhancement

  What is the current behavior?

• In webui, one can call Vendor/Customer return creation from any HU even if it doesn't fit the requirement for returning.

  Which are the steps to reproduce?

• Go to Material receipt, select a HU
• => NOK: The Action "Create Return From Customer"is available
• Press the action button
• => NOK : The customer return document is actually created. This should not happen

  What is the expected or desired behavior?

• The action "Create Return From Customer" shall only be available for HUs with status Shipped, that have HU Assignments to shipment lines.
• The action "Create Vendor Returns" shall only be available to HUs that have HU Assignments to receipt lines.
• The action "Move to garbage" shall only be available to HUs that have HU Assignments to receipt lines.
• The receipt and shipments from the hu assignments above shall be completed or closed.

[teosarca]

NOTE to developer: on webui, the logic shall be called from

• de.metas.ui.web.handlingunits.process.WEBUI_M_HU_ReturnFromCustomer.checkPreconditionsApplicable()
• de.metas.ui.web.handlingunits.process.WEBUI_M_HU_ReturnToVendor.checkPreconditionsApplicable()