Add worker type argument to logical replication worker functions.

Add worker type argument to logical replication worker functions.

Extend logicalrep_worker_stop, logicalrep_worker_wakeup, and
logicalrep_worker_find to accept a worker type argument. This change
enables differentiation between logical replication worker types, such as
apply workers and table sync workers. While preserving existing behavior,
it lays the groundwork for upcoming patch to add sequence synchronization
workers.

Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com