Allow custom `BinderHandler` advise to be applied to the `Binder` used
for `@ConfigurationProperties`. This mechanism has been added to allow
Spring Cloud Stream to manipulate `Bindable` instances before binding
occurs.
NOTE: This commit introduces a breaking change to the `BindHandler`
interface since the `onStart` method now returns a `Bindable` rather
than a `boolean`.
Closes gh-14745
33c2d24560