Proposal: Allow --set/-f for package command

[riccid2]

Would be nice to be able to update values in the values.yaml at package time for things like updating image tags after a build process.

helm package --set image.tag=${BUILD_VERSION} .

[fejta-bot]

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/lifecycle stale

[bacongobbler]

/remove-lifecycle stale
/lifecycle frozen

[bacongobbler]

#3141