Add extra-modify-metadata flag to external-resizer sidecar

[mdzraf]

What type of PR is this? /kind feature

What this PR does / why we need it: This PR adds a flag that can be set by the user which will inject extra PVC and PV metadata as parameters when calling ModifyVolume on CSI Drivers. This will enable CSI Drivers to support StorageClass parameters that depend on the extra metadata in modification via VolumeAttributesClass as well.

See doc for more info

Which issue(s) this PR fixes: N/A

Special notes for your reviewer: N/A

Does this PR introduce a user-facing change?:

Adds the flag --extra-modify-metadata, which when set to true, will inject extra PVC and PV metadata as parameters when calling ModifyVolume on CSI Drivers

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[k8s-ci-robot]

Hi @mdzraf. Thanks for your PR.

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[ConnorJC3]

/ok-to-test

[gnufied]

Can you rebase this PR?

[mdzraf]

@gnufied I have rebased the PR and all tests have passed, it is ready for review

[gnufied]

/lgtm /approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gnufied, mdzraf

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