add support for utf8view type to Nvl function

[Omega359]

Is your feature request related to a problem or challenge?

Currently Nvl does not directly support Utf8View type but rather casts it to Utf8. It would be good to support Utf8View directly

Describe the solution you'd like

Nvl function supports Utf8View directly without casts.

Describe alternatives you've considered

Leave as is

Additional context

No response

[Omega359]

take