Check overflow when casting floating point value to decimal256

[viirya]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

Part of #2986.

This deals with the case of casting floating point value to decimal256.

Describe the solution you'd like

Describe alternatives you've considered

Additional context

[alamb]

label_issue.py automatically added labels {'arrow'} from #3033