refactor: remove dead API, rename to_disk/config_is_remote_dest, fix perror newlines

- Delete unused public array_list_extend (made static)
- Delete legacy 16-parameter parallel_scanner_create wrapper; migrate test to parallel_scanner_create_with_options
- Rename to_disk -> file_write_to_disk and is_remote_dest -> config_is_remote_dest for module_action naming convention
- Remove stray newlines in perror calls (perror already appends one)

src/shared/array_list.c

@@ -34,7 +34,7 @@ void array_list_delete(ArrayList* array_list) {
   free(array_list);
 }
 
-bool array_list_extend(ArrayList* array_list) {
+static bool array_list_extend(ArrayList* array_list) {
   if (array_list == NULL)
     return false;
   int new_capacity = array_list->capacity * 2;