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

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/3e8e05596a020f043f1efd6406e4511ea85170bd

Modified Files
--------------
src/backend/commands/subscriptioncmds.c | 4 +--
src/backend/replication/logical/launcher.c | 40 +++++++++++++++++++----------
src/backend/replication/logical/syncutils.c | 3 ++-
src/backend/replication/logical/tablesync.c | 11 +++++---
src/backend/replication/logical/worker.c | 8 +++---
src/include/replication/worker_internal.h | 9 ++++---
6 files changed, 49 insertions(+), 26 deletions(-)