[C++][Gandiva] Implement Find_In_Set Function

[asfimport]

Returns the first occurrence of str in strList where strList is a comma-delimited string. Returns null if either argument is null. Returns 0 if the first argument contains any commas.

Reporter: Vinicius Souza Roque / @ViniciusSouzaRoque

PRs and other links:

• GitHub Pull Request #12391

_{Note: This issue was originally created as ARROW-15644. Please see the migration documentation for further details.}