Upgrade to contra-tracer 0.2.1

[f-f]

Description

As part of the integration for 11.1, we'll be removing the legacy tracing iohk-monitoring-framework - that needs contra-tracer >= 0.2.1, which this patch implements.

Notes:

• this is a starting point that compiles so I can integrate it downstream, @IntersectMBO/ouroboros-network-maintainers please feel free to take over if it's the wrong approach
• I had to add an SRP to the git repo because the cabal.project file is set to override hackage packages with the CHaP ones, and we already have a contra-tracer on CHaP as well, set to an earlier version. I am not sure what a better approach would be, so I'd be happy to hear suggestions on this (also for future occurrences)

Checklist

Quality

• Commit sequence makes sense and have useful messages, see ref.
• New tests are added and existing tests are updated.
• Self-reviewed the PR.

Maintenance

• Linked an issue or added the PR to the current sprint of ouroboros-network project.
• Added labels.
• Updated changelog files.
• The documentation has been properly updated, see ref.

[coot]

It LGTM, you just need to fix warnings since Contra.Tracer re-exports the >$<, and you'll also need to add QuickCheck < 2.18 constraints, since it renamed/deprecated a function we use.

[f-f]

@coot thanks! I have applied the changes but I am getting a few test failures, could you have a look at those?