Shrine - set hint text to products to indicate what happens when you tap them (1)

[rami-a]

Acceptance Criteria

• Semantic hint that indicates that tapping products will add them to cart

[perclasson]

This is already added for TalkBack for Android. For VoiceOver it does not read the onTapHint. Not sure if this is expected or not. Will investigate further...

[perclasson]

Found that this is intended behaviour:
https://api.flutter.dev/flutter/semantics/SemanticsHintOverrides-class.html

Will have to add a separate hint for VoiceOver.