[TAX] Reviw tax concept and Purchase Worklow

[SMEWebify]

1. on a product in its cost we must be able to indicate what VAT we must apply to it. For example our granite slices come from Italy so the VAT is "Intracom Export", this type of information is useful for accounting.

2. we can have VAT at 0 for Intracom Export or VAT at 0 for reverse charge.

3. Same for VAT 20 installation package and VAT 20 just supply. We must distinguish between VAT 20 when we have an installation service for the customer

[SMEWebify]

• Add Tax id to purchase line
• use default tax setting

[SMEWebify]

Check #508 for defaut VAT