ArrayDataget_slice_memory_size or similar

[alamb]

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

As part of implementing an Arrow flight client, we have observed that there is a maximum message size for gRPC messages, and thus while encoding the Arrow flight client has a way to limit the size of the messages (see #3391)

However, apparently there is currently no way to get the memory size used by a sliced (aka the array only points to a portion of the overall underlying allocation), which will result in overly conservative re-splitting in the arrow-flight client

Describe the solution you'd like
As suggested by @tustvold on #3391 (comment)

It is worth noting that this method does not take into account already sliced arrays, we likely need to add a get_slice_memory_size or something to ArrayData to provide this, it should be relatively straightforward

Describe alternatives you've considered
We could leave the users of the client to worry about batch splitting

Additional context

[askoa]

I'll give this a try.

[alamb]

Thank you @askoa

[tustvold]

label_issue.py automatically added labels {'arrow'} from #3501

[tustvold]

label_issue.py automatically added labels {'arrow-flight'} from #3391