Filter out initial logical replication sync workers

* Slots are crated for each table during the initial sync, which only
  live for the duration of the copy for that table.

* The initial sync backend workers' names are also based on the table
  being copied.

* Filter out the above in Zabbix discovery based on application_name and
  slot_name.

zabbix_templates/pgmon_templates.yaml

@@ -1572,6 +1572,12 @@ zabbix_export:
           type: HTTP_AGENT
           key: pgmon_discover_rep
           delay: 10m
+          filter:
+            conditions:
+              - macro: '{#APPLICATION_NAME}'
+                value: '^pg_[0-9]+_sync_[0-9]+_[0-9]+$'
+                operator: NOT_MATCHES_REGEX
+                formulaid: A
           lifetime: 30d
           enabled_lifetime_type: DISABLE_NEVER
           item_prototypes:
@@ -1775,6 +1781,8 @@ zabbix_export:
                   value: Raw
           url: 'http://localhost:{$AGENT_PORT}/discover_rep'
           lld_macro_paths:
+            - lld_macro: '{#APPLICATION_NAME}'
+              path: $.application_name
             - lld_macro: '{#CLIENT_ADDR}'
               path: $.client_addr
             - lld_macro: '{#REPID}'
@@ -1786,6 +1794,12 @@ zabbix_export:
           type: HTTP_AGENT
           key: pgmon_discover_slots
           delay: 10m
+          filter:
+            conditions:
+              - macro: '{#SLOT_NAME}'
+                value: '^pg_[0-9]+_sync_[0-9]+_[0-9]+$'
+                operator: NOT_MATCHES_REGEX
+                formulaid: A
           item_prototypes:
             - uuid: 536c5f82e3074ddfbfd842b3a2e8d46c
               name: 'Slot {#SLOT_NAME} - Confirmed Flushed Bytes Lag'