RE 2877 Jira<->Changeset traceability for solidity changes

[HenryNguyen5]

This PR adds traceability to our solidity changes, such that when we generate artifacts for review, we have a full trail of jira issues that were used to generate these code changes.

Note: Since these are tightly bound to changesets, I've moved the changeset GHA code from changeset.yml to solidity-traceability.yml to colocate them

e2e Test Cases

Enforcement Stage (This is when we ensure the right metadata is being added for traceability during artifact generation)

• A changeset must exist when opening a PR with solidity changes
• If the changeset does not contain the jira issue number extracted from a commit / branch / PR title, then the job should append one in for the user and push it back to their PR branch for them
• There can be at most one changeset per PR that contains solidity changes, otherwise we don't know which changeset to append the jira issue number to

Traceability Stage (This is when we consume the metadata from the previous stage to create links / backlinks for traceability of our solidity changes between two refs)

• When a workflow_dispatch event is sent to the artifact generation workflow, there should be a list of affected changesets
• All issue numbers should be extracted from the affected changesets
• A URL should be set as an output from the action, which is then used to post to the step summary of the artifact generation job. This URL links out to all affected issues. NOTE: We should just link to the label instead.
• All affected issues should have an artifact URL posted as a comment to them, if the artifact URL does not exist already. This should be job re-run tolerant.
• All affected issues should have a label that links them all together, the label should be relevant to the artifact generation parameters, this should be job re-run tolerant.

[Tofel]

@HenryNguyen5 artifact generation pipeline is available in develop: https://github.com/smartcontractkit/chainlink/actions/workflows/solidity-foundry-artifacts.yml

Also... we will have changesets that do not have any JIRA issues :/ So this step should be fault-tolerant for now.

[cl-sonarqube-production]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
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