Improve the test results for Integrations internals

[Swiddis]

Description

I was debugging some tests locally and it stood out that the errors aren't that useful: most of them are result.ok assertions of the form "Expected true but got false." This is inactionable without custom debugging logic (usually well-placed console.logs). I've added some result helpers that can check results with context, and show the specific errors on failure. Failures should be actionable.

After implementing, I tried introducing some random errors in our integration configs and parsing logic, and verified that the failures made sense.

Issues Resolved

N/A

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[Swiddis]

note: Another option is to extend expect directly

This saves having to tweak the lint config, but I felt the interface was too complicated. We ultimately don't need anything too sophisticated here.

[ps48]

Does this mean all this while tests were actually working?
Also is this related? https://github.com/opensearch-project/dashboards-observability/pull/1319/files#diff-d5d5f677efd1b143b889952745e8485394751aa2d0ec93020befc186c2e621ee

[Swiddis]

That file is also related by virtue of it being the same sort of result validation. We could use the same helpers there as well if we touch the file again. I didn't migrate everything since there's probably a lot of migration to do and the exact syntax for how I checked it in different places isn't consistent (which goes to show the necessity for a standard form...)

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/dashboards-observability/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/dashboards-observability/backport-2.x
# Create a new branch
git switch --create backport/backport-2376-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 cd70e059a6d1616fe7bbe8dc2cc1157e59394deb
# Push it to GitHub
git push --set-upstream origin backport/backport-2376-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/dashboards-observability/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-2376-to-2.x.