8.0 remove Purchase Requisition creation wizard

- Remove Button on Logistics Requisition Source to let those 2 options to create a Purchase Requisition:
  1. Standard way: 
      view: Logistics Requisition Line Form
      action: Button Create Purchase Requisition on Form
      Aim: Create a Single Purchase requisition for all Sources in Tender

  2. Advanced way:
     view: LR Source List
     action: More -> Create Purchase Requisition on Form
     Aim: Select precisely which Source you want in same Purchase Requisition

- Remove completely the code of the former Purchase Requisition Wizard
why do you use `self.mapped('source_ids')` instead of `self.source_ids`? I would understand if `self` could be a recordset with many records but here it is decorated with `@api.one`.