Support getting products list with a callback to the js side

[skalber-mm]

From the docs:

// It takes some time to get product info, we can check if it was already made
if (purchaseManager.productRequestWasMade()) {
}

How can the caller know when the request finished?

[jdarowski]

It isn't implemented yet. As you can see in the readme, I've bypassed it by launching the request right after the initialisation.

MFInAppPurchaseManager *purchaseManager = [[MFInAppPurchaseManager alloc] initWithProductIDs:@[@"my_super_product", @"my_other_super_product"]];
    [purchaseManager requestProductInfo]; // This line is optional, you can do it later on demand

However I see that this is a serious issue and I plan on fixing this in the near future.