[C++] Add option for casting failure values to default to NULL/NA

[asfimport]

In ARROW-16833, a user is complaining that they are unable to cast their messy string data to integer data and they receive an error message.  In R, it's possible to convert this kind of data to integers, with values that fail just being converted to NA values.  Would it be possible to enable this as an option in Arrow?

Reporter: Nicola Crane / @thisisnic

_{Note: This issue was originally created as ARROW-16862. Please see the migration documentation for further details.}

[github-actions]

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