[ADD][8.0] : Dynamic Price for POS

For more details see README file at : 
https://github.com/taktik/pos/tree/8.0-pos_dynamic_price/pos_dynamic_price
Yeah absolutely. For v8.0 there no solution for this missing feature !
You can check this discussions : 
https://github.com/odoo/odoo/issues/3401#issuecomment-63807499
https://github.com/odoo/odoo/issues/3500