SPM-4079 aims to unify the router role loop for handling StaleConfig errors. However, the router role loop can't be reused on the write path because the path for capturing an error and the retry operations are too complex to be placed on a simple retryable loop.

Nevertheless, the write path is calling the RoutingContext::onStaleError in order to flag the routing cache as stale. This code can be unified with the code in router_role to avoid duplications and decrease the mainentance effort of the codebase.

The goal of this ticket is to:

• Remove the RoutingContext::onStaleError function along with its usages.
• Add the same method under the router library.
• Reuse this method under the DBPrimaryRouter and CollectionRouterCommon.