Rename CallSolver --> CreateAutoShardingSolverRequestAndCallSolver and CallORToolsSolver --> FormulateAndSolveMIPFromAutoShardingSolverRequest to better capture the function implementation.

Rename CallSolver --> CreateAutoShardingSolverRequestAndCallSolver and CallORToolsSolver --> FormulateAndSolveMIPFromAutoShardingSolverRequest to better capture the function implementation. #2866