Support for quotes and orders

Added functionality for working with quotes and converting orders to sales invoices

Changelog

• added: GET v2/quotes
• added: GET v2/quotes/{id}
• added: DELETE v2/quotes/{id}
• added: POST v2/quotes
• added: PUT v2/quotes/{id}/accept
• added: POST v2/quotes/{id}/converttoorder
• added: POST v2/quotes/{id}/converttocustomerinvoice
• added: GET v2/quotedrafts
• added: GET v2/quotedrafts/{id}
• added: DELETE v2/quotedrafts/{id}
• added: POST v2/quotedrafts
• added: PUT v2/quotedrafts/{id}
• added: PUT v2/quotedrafts/convert
• added: POST v2/orders/{id}/convert