Extend object-access hook machinery to support post-alter events.

This also slightly widens the scope of what we support in terms of
post-create events.

KaiGai Kohei, with a few changes, mostly to the comments, by me

src/backend/commands/tsearchcmds.c

@@ -612,6 +612,8 @@ AlterTSDictionary(AlterTSDictionaryStmt *stmt)
 
 	CatalogUpdateIndexes(rel, newtup);
 
+	InvokeObjectPostAlterHook(TSDictionaryRelationId, dictId, 0);
+
 	/*
 	 * NOTE: because we only support altering the options, not the template,
 	 * there is no need to update dependencies.  This might have to change if
@@ -1184,6 +1186,9 @@ AlterTSConfiguration(AlterTSConfigurationStmt *stmt)
 	/* Update dependencies */
 	makeConfigurationDependencies(tup, true, relMap);
 
+	InvokeObjectPostAlterHook(TSConfigMapRelationId,
+							  HeapTupleGetOid(tup), 0);
+
 	heap_close(relMap, RowExclusiveLock);
 
 	ReleaseSysCache(tup);