chore: Add name label to chaos_experiments metric

[miketonks-form3]

We need to be careful about cardinality, but since we won't have hundreds of chaos experiments it should be ok to add name, given that is really useful for dashboards and alerting

Removed the expCache to simplify code

What problem does this PR solve?

What's changed and how it works?

Related changes

• This change also requires further updates to the website (e.g. docs)
• This change also requires further updates to the UI interface

Cherry-pick to release branches (optional)

This PR should be cherry-picked to the following release branches:

• release-2.6
• release-2.5

Checklist

CHANGELOG

Must include at least one of them.

• I have updated the CHANGELOG.md
• I have labeled this PR with "no-need-update-changelog"

Tests

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• Unit test
• E2E test
• Manual test

Side effects

• Breaking backward compatibility

DCO

If you find the DCO check fails, please run commands like below (Depends on the actual situations. For example, if the failed commit isn't the most recent) to fix it:

git commit --amend --signoff
git push --force

[github-actions]

Created new release based on commit 4d7ad40

Release tag: v2.6.1-f3-4d7ad-mike-metrics-with-name

Link to release