Split the contour benchmark into structured/unstructured

We've been having problems with PerformanceTestBenchContour. In the last few iteration, the runtime goes way up. We cannot find any reason for this in the source code. There don't appear to be any particular problems with memory or tables. The best we can figure is an issue with the device hardware in the container.

The easy solution should be to break the benchmark into smaller peices to avoid the problem.

This is a backport of !3229 (merged) into the 2.1 release branch.