Add annotations to data-volume volumeClaimTemplate

[muckelba]

Hey, thanks for providing a chart, it helps me a lot! I was missing the ability to add annotations to the PVC created by the StatefulSet so i thought i can just contribute that. During that i noticed that a default value for the affinity was missing so i added that too

I'm not 100% sure about your release workflow. I bumped the patch version of the chart for now, or should that not diverge with the app version?