Add typed collection to BUYCollection.

Mobile Buy SDK/Mobile Buy SDK/Models/Persistent/BUYCollection.h

@@ -31,6 +31,8 @@
 
 @property (nonatomic, readonly) NSString *stringDescription;
 
+- (NSArray<BUYProduct *> *)productsArray;
+
 /**
  *  Converts the BUYCollectionSort enum to an API-compatible string for the collection sort parameter
  *

Mobile Buy SDK/Mobile Buy SDK/Models/Persistent/BUYCollection.m

@@ -32,6 +32,11 @@
 
 @synthesize stringDescription = _stringDescription;
 
+- (NSArray<BUYProduct *> *)productsArray
+{
+	return self.products.array;
+}
+
 - (void)updateStringDescription
 {
 	// Force early cache of this value to prevent spooky behaviour