In our grouping algorithm, we ignore recursion, that is to say, we count n consecutive copies of a frame the same as if there were just 1 copy. Currently, in order to do this, we have the stacktrace strategy compare successive frames, and if recursion is detected, we add a flag to the grouping context so that all frames but the first in a recursion mark themselves as non-contributing. This works, but is more complicated than it needs to be.

To simplify things, this PR lets the stacktrace component mark recursive frames non-contributing rather than having the frames do it themselves. This saves us from having to transmit that data through to the frame strategy, and therefore means we don't need to include the data in the grouping context.