Send productImpressions in batch instead of sending for each product

[klzns]

Today productImpression is being sent separately for each product on the shelf. For each product we trigger a hit to GA and eventually that can exceed a limit stablished in the contract. To save hits we should send them in batches so we hit GA fewer times.

We should beware that there's a limit of 8kb for a hit, that can happen if we send more than 50 products in a hit, for example. One solution for that is to send only productImpressions of products visible in the screen.

Possible Solution

We might use context in the Shelf component to listen to events triggered by each product and then trigger the event after some miliseconds.

We could also use intersectionobserver to trigger only events to products visible on the screen.

Steps to Reproduce (for bugs)

Open a store with a shelf and see that productImpression is sent N times.