Name the gates and phased barriers we use
to make it easy to debug gate_closed_exception
Refs https://github.com/scylladb/seastar/pull/2688
* Enhancement only, no backport needed
Closesscylladb/scylladb#23329
* github.com:scylladb/scylladb:
utils: loading_cache: use named_gate
utils: flush_queue: use named_gate
sstables_manager: use named gate
sstables_loader: use named gate
utils: phased_barrier, pluggable: use named gate
utils: s3::client::multipart_upload: use named gate
utils: s3::client: use named_gate
transport: controller: use named gate
tracing: trace_keyspace_helper: use named gate
task_manager: module: use named gate
topology_coordinator: use named gate
storage_service: use named gate
storage_proxy: wait_for_hint_sync_point: use named gate
storage_proxy: remote: use named gate
service: session: use named gate
service: raft: raft_rpc: use named gate
service: raft: raft_group0: use named gate
service: raft: persistent_discovery: use named gate
service: raft: group0_state_machine: use named gate
service: migration_manager: use named gate
replica: table: use named gate
replica: compaction_group, storage_group: use named gate
redis: query_processor: use named gate
repair: repair_meta: use named gate
reader_concurrency_semaphore: use named gate
raft: server_impl: use named gate
querier_cache: use named gate
gms: gossiper: use named gate
generic_server: use named gate
db: sstables_format_listener: use named gate
db: snapshot: backup_task: use named gate
db: snapshot_ctl: use named gate
hints: hints_sender: use named gate
hints: manager: use named gate
hints: hint_endpoint_manager: use named gate
commitlog: segment_manager: use named gate
db: batchlog_manager: use named gate
query_processor: remote: use named gate
compaction: compaction_state: use named gate
alternator/server: use named_gate