[benchmark] Refactor: type independent variants

Benchmarks from Array group (except the `init`) don’t use the `withType` parameter from the `run_` function anymore. The type specific variation is taken care of in the `BenchmarkInfo`, since the `existentialArray` with appropriate type is created by the `setUpFunction`. This means we can reuse the same non-generic `run_ ` function for the whole group and eliminate all the specialized `runFunction` variants.

This eliminates 144 lines of boilerplate.

Author: palimondo