Fix: deprecation log, UTF-8 in resource plugin, retry interrupt, permission constants

[rbaddam]

Backward compatible code fixes like warn when server.websockerUrl is used, use UTF-8 in the resource plugin, throw on retry interrupt instead of returning null, and name the persist permission constants. No API or config changes.

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[rbaddam]

@ibodrov @benbroadaway @brig : Could you please review the PR, thanks