feat: Allow specifying additional labels to be applied to all helm chart resources

[laverya]

Why is this PR required? What issue does it fix?:

There is currently no way to specify additional labels to be applied to the resources in the chart - only the pod itself, not even the deployment that creates those pods.

What this PR does?:

Adds a top-level labels map within the values file. If it is populated, these labels will be added to the storageclass directly, and also to the 'localpv.labels' variable, which is already included within every resource besides the storageclass.

Does this PR require any upgrade changes?:

No

If the changes in this PR are manually verified, list down the scenarios covered::

I rendered the yaml with helm template ./deploy/helm/charts with both an empty and populated labels map, and validated that labels were created in the approprate places.

Any additional information for your reviewer? : Mention if this PR is part of any design or a continuation of previous PRs

Checklist:

• [ ] Fixes #
• [ ] PR Title follows the convention of <type>(<scope>): <subject>
• [ ] Has the change log section been updated?
• [ ] Commit has unit tests
• [ ] Commit has integration tests
• [ ] (Optional) Are upgrade changes included in this PR? If not, mention the issue/PR to track:
• [ ] (Optional) If documentation changes are required, which issue on https://github.com/openebs/openebs-docs is used to track them:

PLEASE REMOVE BELOW INFORMATION BEFORE SUBMITTING

The PR title message must follow convention: <type>(<scope>): <subject>.

Where: Most common types are: * feat - for new features, not a new feature for build script * fix - for bug fixes or improvements, not a fix for build script * chore - changes not related to production code * docs - changes related to documentation * style - formatting, missing semi colons, linting fix etc; no significant production code changes * test - adding missing tests, refactoring tests; no production code change * refactor - refactoring production code, eg. renaming a variable or function name, there should not be any significant production code changes * cherry-pick - if PR is merged in master branch and raised to release branch(like v0.4.x)

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[laverya]

Is this something that you would consider?

[avishnu]

We shall take a look. Thanks for this.

[laverya]

Sounds good, thank you for the review/approval/promise of future merging!

[niladrih]

@laverya -- I've taken up your change in #194. It'll be included in v4.1.0. I've made some minor changes to support upgrades with --reuse-values. You should be still able to label all of the chart resources though. Closing this PR.

[laverya]

Thank you, and have a happy Fourth of July!

[niladrih]

Thank you, and have a happy Fourth of July!

Thank you, and wish you the same :)