Explicitly pass out_file to benchcomp visualizers

[karkhaz]

This commit adds an out_file to the benchcomp visualizes that emit output (currently just one visualization, dump_yaml). This is to allow different visualizations to be written to different output files, including stdout.

The intention (for a future commit) is that CI will save certain visualizations as artifacts, which users can then download.

Testing:

• How is this change tested? Ran it locally

• Is this a refactor change?

Checklist

• Each commit message has a non-empty body, explaining why the change was made
• Methods or procedures are documented
• Regression or unit tests are included, or existing tests cover the modified code
• My PR is restricted to a single feature or bugfix

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.

[tautschnig]

This is not currently possible because the Action will fail if there were any regressions, meaning that the artifact would not be subsequently uploaded. This will be addressed in a future commit that allows particular visualizations to run.

I don't think this statement is true: https://github.com/actions/upload-artifact will happily upload artifacts even if an earlier step failed (there even is provision to only do so when an earlier step failed, see their docs). We make good use of this in https://github.com/diffblue/cbmc/blob/develop/.github/workflows/build-and-test-Linux.yaml, which will upload files to debug build failures.

[karkhaz]

You're right, thank you. I've amended the commit message.