[C++] Improve configurability of RandomArrayGenerator::ArrayOf

[asfimport]

#7410 (comment)

RandomArrayGenerator::ArrayOf only accepts the length and null_probability of the generated array as parameters. It could define an options struct to allow test cases to specify type-dependent properties like numeric extrema, string lengths, etc

Reporter: Ben Kietzman / @bkietz

Related issues:

• [C++] Improve configurability of random data generation (is superceded by)

_{Note: This issue was originally created as ARROW-9149. Please see the migration documentation for further details.}