[controller] add a new config that, when set, will update real time topic during partition count update

[arjun4084346]

update real time topic name, if needed during partition count update, when config update.real.time.topic is set

With this PR, during partition count update, we will set the real time topic name if the partition count update is needed.
This is a part of the bigger project to achieve re-partitioning in real time topic and because there is a lot of work remaining, we will control this behavior through a config update.real.time.topic; the default value of this config will be false

Resolves #XXX

How was this PR tested?

Does this PR introduce any user-facing changes?

• No. You can skip the rest of this section.
• Yes. Make sure to explain your proposed changes and call out the behavior change.