ARROW-12715: [C++][Python] Add SQL LIKE match kernel

[lidavidm]

Implements a simple SQL LIKE pattern match kernel by translating it to a regex (or substring) match as appropriate.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-12715

[ianmcook]

LGTM, thanks for doing this @lidavidm!

[ianmcook]

P.S. case insensitivity can be achieved by using one of the _upper or _lower kernels, which I think is good enough

[lidavidm]

We could easily add a flag to toggle insensitivity in RE2 as well. (Would be better than allocating a new string and potentially dealing with Unicode.)

[ianmcook]

But can PlainSubstringMatcher do case-insensitive matching?

[lidavidm]

No, but in that case we'd just not dispatch to that path.

[ianmcook]

What to do about the options class might be awkward. You could subclass MatchSubstringOptions, but I think ultimately we might incorporate an option for case insensitivity into MatchSubstringOptions.

[lidavidm]

We could add it to MatchSubstringOptions, if we plan to support for all kernels, and leave it unimplemented for now in the non-regex case (it's pretty easy to support in any regex case).

[ianmcook]

Sounds good. The case-(in)sensitive option should be optional and should default to case-sensitive. We should error in cases where case-insensitive match is specified in the options but is ignored by a kernel or by any path in a kernel. This sounds to me like a separate PR. Should I open a Jira for that?

[lidavidm]

I filed ARROW-12835. I think this PR should be otherwise good-to-go then, unless we need to also add R bindings.

[ianmcook]

I think it's good to go. Nothing is needed in the R bindings.

[lidavidm]

Merged, thanks for the review!