Add `MINIO_API_EXTEND_LIST_CACHE_LIFE` that will extend
the life of generated caches for a while.
This changes caches to remain valid until no updates have been
received for the specified time plus a fixed margin.
This also changes the caches from being invalidated when the *first*
set finishes until the *last* set has finished plus the specified time
has passed.
configurable remote transport timeouts for some special cases
where this value needs to be bumped to a higher value when
transferring large data between federated instances.
