Added Xfail and Mayfail attributes to city runner

[coldav]

Overview

Support attribute Xfail and Mayfail for city runner and an add a --override option to override entries in the main csv file.

Reason for change

We want to be able to run tests that we know fail, but we don't want an overall fail.

Description of change

Added xfail and Mayfail as attributes to city runner.

Xfail means we expect it to fail and will give a failing return code if it unexpectedly pass, otherwise it does not contribute to an overall fail.

Mayfail means it sometimes fails and will not contribute to a failing return code.

Unlike some of the other attributes, these cannot be set with additional csv files, as it was felt this leads to overcomplexity. Instead it is expected that some form of csv combination script could be used alongside this.

Added --override option. This provides an additional csv file which can override entries in the main csv file if it matches the first two values in an entry. This is useful for overriding attributes such as Xfail.

Anything else we should know?

The following is example output

dump.txt

Checklist

• Read and follow the project Code of Conduct.
• Make sure the project builds successfully with your changes.
• Run relevant testing locally to avoid regressions.
• Run clang-format-19 on all modified code.

[hvdijk]

Looks pretty good! Some odd whitespace and perhaps slightly more verbose naming and complicated logic than needed, left some suggestions for that, but the logic for the results looks right as far as I can see