Merge branch 'main' into metadata-transfer, resolve conflicts

Conflicts resolved:
- config_create signature: added both use_metadata and use_sendfile params
- config_send/config_receive: wire protocol includes both use_metadata and use_sendfile
- client.c: config_create call updated, arg parsing includes both -M/--preserve and -f/--sendfile
- test_config.c: all three config_create calls updated
- file_send_sendfile: use file->data->size instead of removed struct stat

src/shared/file.h

@@ -23,6 +23,7 @@ void file_destroy(void *item);
 void file_load_data(File *file);
 void file_print(void *item);
 void file_send_single_calls(File *file, int file_descriptor);
+void file_send_sendfile(File *file, int file_descriptor);
 size_t file_content_to_buffer(File *file);
 FileMetadata *file_metadata_create(struct stat *stats);
 void file_metadata_destroy(void *metadata);