Add the ability to do constraints over trees in constrained-generators

[MaximilianAlgehed]

Description

Also fixes some minor issues around list size

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated. If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages. New section is never added with the code changes. (See RELEASING.md)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[TimSheard]

I love the clarity of the module Tree.hs
The examples are also clear as a bell.
Good to go, Thanks Max for such a sweet extension.

[UlfNorell]

@lehins I'm having trouble figuring out why CI failed. It says

Tests failed for test:cardano-ledger-shelley-ma-test

but I can't for the life of me find the failing test in the log.

[lehins]

@UlfNorell Here is the reason

This is the flaky test that has been haunting us for the longest time. It is caused by the older trace generation framework that was written back in times of Shelley.
Once we are done with Conway we'll invest some time into fixing it, but for now we are forced to suffer through it. So, feel free to re-run the build.

[UlfNorell]

I don't think I have permissions to restart tests runs. At least I can't find the button where I remember it being.

[lehins]

I don't think I have permissions to restart tests runs.

That is strange. You do have write permission to the repo, so you should be able to restart GithubActions CI (FYI, hydra CI is not required, so there is no need to restart if there are failures)

At least I can't find the button where I remember it being.

It should be right here:

[MaximilianAlgehed]

I have restart rights. I decided to force push here because it was faster. The time is dominated by the 8.10.7 build - so waiting for that to finish before doing a restart (you can't restart while things are running) would be slower. However, I guess the best option would have been to cancel the 8.10 job and then re-start both the failed and 8.10 job. Good to remember next time.