Implement bugfix for chart dependencies and gitops.

[komish]

~Do Not Merge.~

~I will remove :point_up: if and when this this is valid to merge/review. I have intentionally not applied the draft label because this prevents certain CI operations from running.~

[EDIT] This is ready for review.

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This PR contains all of the impactful changes to how the certification pipeline works in order to resolve issues when depending on charts we provide.

In effect, this PR enables:

• Locked helm chart name tracking and generation
• Checks on OWNERS file submission to ensure locks are respected
• Fixes indexing strategy to index on chart names only

In addition, this PR includes E2E testing extensions for some of the new logic.

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Change summary by file:

.github/workflows/mercury_bot.yml

• Only run this on changes to partner OWNERS files.
• Make sure that the incoming content is valid.
• Make sure the incoming chart name is not locked.

scripts/src/checkprcontent/checkpr.py

• Make sure we're adding the chart name to the github output.
• Ensure redhat charts follow proper standards at chart content check time. This is a secondary check to the one that's executed at OWNERS file submission time via GHA.
• Ensure the index key is set to the chart's name (changed from org-chart).

tests/functional/behave_features/common/utils/chart_certification.py

• Ensure the index key is set to the chart's name (changed from org-chart).

tests/functional/behave_features/environment.py

• Defines the OWNERS file testing fixture
• Adds the fixture to the scenario when the proper references are added in the scenario tests

.github/workflows/owners-redhat.yml (new)

• On Red Hat OWNERS file submissions, will check to make sure that the content matches standards.

.github/workflows/lock-sanity-check.yml (new)

• Sanity checks chart lock workflows by running on every main push, and notifying on failures.

.github/workflows/check-locks-on-owners-submission.yml (new)

• Ensures new redhat/community owners files do not encroach on locks.

tests/functional/behave_features/HC-20_owners_file.feature (new)

• Defines the new Helm Cert E2E test for OWNERS files,

tests/functional/behave_features/steps/implementation_owners.py (new)

• Implements the new Helm Cert E2E test for OWNERS files.

[komish]

@mgoerens I believe I've addressed everything you've requested.

Re: Newlines between steps. I've received that feedback before. I don't find it strictly necessary, but I also don't mind it at all. If I've missed them, I'm happy to add them. If it doesn't happen in this PR, I can go back and normalize all workflows at the same time that I'm standardizing on a single github runner image (e.g. the ubuntu-22.04 change).