Spring Use suspending style filter function in Kotlin code sample

This is really a question in the form of a PR. Is this code sample equivalent of the original (assuming renewToken is a suspend function)?

Comment From: jbotuck

@sdeleuze

Comment From: sdeleuze

Are there any plans for a CoExchangeFilterFunction?

After a related discussion with @poutsma, we think that the proper way to move forward is to introduce indeed a CoExchangeFilterFunction as part of Spring Framework 6.1, then update the documentation to leverage it. Please create a related issue and we will likely implement it.

As a consequence, I close this PR unmerged.