fix(ep-commerce): mark EPProductProvider as providesData

[field123]

Summary

• One-line meta fix on EPProductProvider: providesData: true.
• Without it Plasmic compiles the component's children slot inline at the parent's render scope, so $ctx.currentProduct.* bindings inside the slot evaluate where currentProduct doesn't exist yet (the <DataProvider name="currentProduct"> the component publishes only takes effect for descendants).
• With it, the compiler wraps the slot in a descendant function-component with its own useDataEnv() — currentProduct resolves correctly and PDPs that wire product to a Plasmic Server Query ($q.<name>.data) actually render the product data instead of throwing TypeError: Cannot read properties of undefined (reading 'name').
• Matches every sibling data-providing component in the same package (EPCartProvider, EPBundleProvider, EPVariationPicker, EPProductListProvider, etc. — all 11 already declare providesData: true). Looks like the flag was simply missed when EPProductProvider was first added.

Test plan

• In a consumer app with a Plasmic page whose EPProductProvider.product is bound to $q.<query>.data (Server Query returning a Product), pre-fix: page render throws Cannot read properties of undefined (reading 'name') from any binding inside the provider's slot.
• After this fix + a rebuild of @elasticpath/plasmic-ep-commerce-elastic-path, the same page renders the product's name, description, price, image etc. correctly.
• Existing consumers of EPProductProvider that use the legacy client-fetch path (productId prop, no product prop binding) keep working — providesData: true is purely additive at the Studio code-gen level and doesn't change runtime behaviour for the component itself.