Introduce User Group Pricing to the price selector Price Selector

[JustShah]

Summary

Overview:

This pull request introduces enhancements to the pricing system in the Spree application by implementing user group-specific pricing. The changes allow for dynamic price selection based on user groups, enabling more flexible and differentiated pricing strategies for various customer segments.

Key Changes:

1. Price Selector by User Group:

   • Added the Spree::Variant::PriceSelectorByUser Group class, which is responsible for selecting the appropriate price for a product variant based on user group pricing options.
   • This class allows for user group-specific pricing by incorporating user group information along with other pricing factors such as country and currency.
   • The price selector can be configured in the Spree initializer:

     Spree.config do |config|
       config.variant_price_selector_class = 'Spree::Variant::PriceSelectorByUser Group'
     end

2. Pricing Options with User Group:

   • Introduced the Spree::Variant::PricingOptionsWithUser Group class to define the necessary pricing attributes (currency, country, user group) for selecting prices.
   • This class provides a flexible way to manage pricing options that consider user groups, allowing for complex pricing models where different user groups may receive different pricing for the same product variant.

3. New Scope in Price Model:

   • Added the without_pricelist scope to the Spree::Price model, enabling filtering of prices that are not associated with any price list.
   • This scope allows the system to differentiate between prices managed by price lists and standalone prices, facilitating more precise querying and filtering.

Benefits:

• Enhances the pricing flexibility of the Spree application by allowing for user group-specific pricing.
• Supports more complex pricing strategies tailored to different customer segments.
• Improves the ability to manage and query prices effectively within the system.