feat: add language switcher based on localized slugs coming from Spree

[fpdrozd]

Description

This PR adds the localized_slugs property to product and taxon serializers making it accessible on the frontend. Then it is being parsed by the localizedSlugsToRouteParams function and passed to the i18n/setRouteParams dispatch to set the alternative routes (docs).

Related Issue

Motivation and Context

When switching between languages on product and category page the user should be redirected to the translated url defined in Spree backend.

How Has This Been Tested?

visually

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.