Fix duplicated test name in Perf.TypeName and update validation

[caaavik-msft]

Due to how the FullNameProvider works, the Dictionary<string, bool>[] and Dictionary<List<int[]>[,], List<int?[][][,]>>[] arguments were both being converted to the string System.Collections.Generic.Dictionary`2[]. Patching this in BenchmarkDotNet would cause too many test names to change, and this is the only case in this repo that there is a duplicate full name, so we can address it by wrapping the type and overriding the ToString.

The display names that I have put here ensure that the test names remain the same as they were before, with only the Dictionary<List<int[]>[,], List<int?[][][,]>>[] case now being converted to typeof(System.Collections.Generic.Dictionary`2[]) (COMPLEX) to differentiate it from the simpler case.

I have also updated the validators to ensure this doesn't happen again.

[caaavik-msft]

@adamsitnik As you had originally added this benchmark, are you able to confirm that the changes to the benchmark by using a wrapper type are acceptable and that adding the property lookup should have a negligible impact on the performance measurement?

[LoopedBard3]

Looks good.