chore(atc_router) add LRU cache support just like the traditional router (#9096)
chore(atc_router) add LRU cache support just like the traditional router (#9096)

This code is copied from the traditional router, we just keep the same logic/behavior as old router.

Maybe we will change it in the future.

Co-authored-by: chronolaw <00a199737e0846da76045404494fe89187cae3b2@me.com>
Kong/kong,Kong/kong,Kong/kong