release-24.3: roachtest: allow adding extra github parameters

[DarrylWong]

Backport 1/1 commits from #134885.

/cc @cockroachdb/release

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When github issue posting, we denote various parameters describing the test, i.e. cloud, metamorphic encryption, etc. This is useful as it allows one to easily determine properties of a test without digging into the logs.

However, this feature only works if github posting is enabled. We've seen some cases where it is not enabled and we have trouble figuring out the aforementioned parameters. This change makes it so the parameters are logged to the artifacts directory if github posting is not enabled.

It also exposes the notion of extra parameters to the test interface. This allows for tests that have metamorphic properties to easily list them in the issue itself.

One example of this is in mixed version tests, where we randomize the deployment mode and the versions used. We often run into issues that pertain to only a specific deployment mode or version, and it can be cumbersome to dig through the artifacts for each individual failure.

Release note: none
Epic: none
Fixes: none

Release Justification: Test infra only change

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Backports should only be created for serious
  issues or test-only changes.
• Backports should not break backwards-compatibility.
• Backports should change as little code as possible.
• Backports should not change on-disk formats or node communication protocols.
• Backports should not add new functionality (except as defined
  here).
• Backports must not add, edit, or otherwise modify cluster versions; or add version gates.
• All backports must be reviewed by the owning areas TL. For more information as to how that review should be conducted, please consult the backport
  policy.

If your backport adds new functionality, please ensure that the following additional criteria are satisfied:

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
• The new functionality is additive-only and only runs for clusters which have specifically “opted in” to it (e.g. by a cluster setting).
• New code is protected by a conditional check that is trivial to verify and ensures that it only runs for opt-in clusters. State changes must be further protected such that nodes running old binaries will not be negatively impacted by the new state (with a mixed version test added).
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.
• Your backport must be accompanied by a post to the appropriate Slack
  channel (#db-backports-point-releases or #db-backports-XX-X-release) for awareness and discussion.

Also, please add a brief release justification to the body of your PR to justify this
backport.

[cockroach-teamcity]

This change is