Rename pluggable logic chain as ArenderRedactCompletion

Looking at https://github.com/nuxeo/nuxeo-arender-connector/blob/aa731ff16dc5223ce8816550a589ce088e42be35/modules/nuxeo-arender-core/src/test/resources/OSGI-INF/test-nuxeo-arender-chain-override-content-redaction-contrib.xml , chain is currently named javascript.ArenderRedactCompletion

=> This creates UX issues with Studio as shown in the video attached: can't create a configuration object with that name, and I am forced into using a script to override it.

Renaming it to ArenderRedactCompletion would allow people to create a chain with that name. It would also force people into using a chain, but automation scripting can be used inside chains, not the other way around.