Max Englander

With @mattlord help I have been benchmarking the performance of this PR alongside #10788. Both PRs improve performance between 10-200%, depending on factors like CPU load on the data source....

Have squashed all the commits. Was too annoying to try to fix the commit that was missing DCO with rebase. Previous commit history preserved [over here](https://github.com/planetscale/vitess/tree/rn-vrep-concurrent-copy-backup) just in case.

@deepthi conflicts resolved and release notes added

@harshit-gangal I implemented the one outstanding suggestion I found (`timeout` => `conn.timeout`), sorry for missing that until now. Also reverted the unrelated fmt changes (used `git commit --no-verify`).

@deepthi fair enough I'll update my comments about table equivalence to reflect. However I think table equivalence in the example in the docs still satisfies the goal of the RFC...

Thanks for the guidance @deepthi and @harshit-gangal. I'm going to start working on option 1.

@harshit-gangal > refer can also point to the unqualified table, which can follow the global routing logic. Is it OK with you if I don't support that initially? Maybe that...

@harshit-gangal > We already have similar automation for MoveTables, CreateLookupVindex, etc. Oh that's cool, didn't know that. Will add something to the RFC about that.

@harshit-gangal > One more thing we should also talk about in the RFC is the automation of updating the Vschema when a materialized workflow is created. Add notes in RFC...

Thanks @rohit-nayak-ps I'll incorporate your notes in the RFC.