[C++] Add re2 library to core arrow / ARROW_WITH_RE2

[asfimport]

For https://github.com/apache/arrow/issues/18312 we need the re2 linked into the core arrow library, as discussed:
#8459 (review)

This might be good to put under an ARROW_WITH_RE2 CMake option, maybe default on when ARROW_COMPUTE=ON?

Reporter: Maarten Breddels / @maartenbreddels
Assignee: Uwe Korn / @xhochy

Related issues:

• [C++] Add string struct extract kernel using re2 (blocks)

PRs and other links:

• GitHub Pull Request #8756

_{Note: This issue was originally created as ARROW-10541. Please see the migration documentation for further details.}

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
I think a minimum to do here is adding a ARROW_WITH_RE2 option (and then we can still see if we also want something like ARROW_COMPUTE_STRINGS that turns on both re3 and utf8proc).

cc @xhochy @pitrou

[asfimport]

Kouhei Sutou / @kou:
Issue resolved by pull request 8756
#8756