Show sort options in CategoryListPage

[sanjeevyadavIT]

Is your feature request related to a problem? Please describe.
Show options to sort products in ascending and descending order based on price and name on CategoryListScreen .

Describe the solution you'd like
Display an option sort on CategoryListScreen, which on click show a dialog with 4 option.

1. sort in ascending order: price
2. sort in descending order: price
3. sort in ascending order: name(a to z)
4. sort in descending order: name(z to a)

On selecting any option, make new request that will get products for that particular category in that order.

Additional context
You can see implementation in troublediehard/magento-react-native
See Issue #13 , similar functionality