Add service template rows

[PavanKumarPacharla]

This PR enhances the flow from Sales Order to Repair Order by automatically linking selected Service Templates in line items to the associated Project during Sales Order submission.

Feature Details:

• When a Sales Order is submitted:
• Each line item is checked for a linked Service Template.
• If present and not already associated with another item, a new Project Service Template row is created.
• This row is inserted into the corresponding Project.
• The service_template_detail field in the Sales Order Item is updated with the newly created row’s name.
• Finally, set_service_template_has_transaction(update=True) is called on the Project to update its state.
• If the same service template is already linked to another sales order item, the process is halted with a clear error message to avoid duplication.

Closes #491