[Woo POS] M2: Handle products loading errors, empty state

[samiuelson]

1. Products are empty and app fails to load them -> display global error as per designs with "Retry" botton
2. Failed to load next page -> automatic retry?

[dangermattic]

🚫 Please add a type label (e.g. type: enhancement) and a feature label (e.g. feature: stats) to this issue.