Change 'render' to 'builder'

[chimon2000]

Is your feature request related to a problem? Please describe. This is to standardize closely to Flutter widgets that use a builder function rather than a render function.

Describe the solution you'd like

1. renderLoad becomes buildLoad
2. renderError becomes buildError
3. renderSuccess becomes buildSuccess

Describe alternatives you've considered N/A

Additional context Add any other context or screenshots about the feature request here.