Proof of concept - Offline browsing

[elkmod]

This Pull Request is a proof of concept for our planned "Offline Browsing" feature.

The approach is holistic, which will ultimately (hopefully) allow us to expand it to multiple areas of the application. Planned scope for the initial implementation:

• Product listings
• Product detail pages
• Search & Search result pages

General key facts

• Layer of abstraction is the shopware-6-client package
• Store structured product data instead of full responses
• Store product data using IndexedDB
• Replicate filter logic locally based on IndexedDB key ranges

More Information here

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