Similar to the binary-encoded string repeat function, we need a compute function for UTF-8 string repeat function.

Reporter: Eduardo Ponce / @edponce
Assignee: Pradeep Garigipati / @9prady9

Related issues:

• [C++] String repeat kernel (is related to)

_{Note: This issue was originally created as ARROW-15197. Please see the migration documentation for further details.}