pxar: add PxarDir and PxarDirBuf to buffer directory metadata

In order to restore only directories when some of their content fully matched
a match pattern on partial restores, these directories and their metadata are
pushed onto this buffer and only restored successivley on demand.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>

src/pxar.rs

@@ -65,4 +65,7 @@ pub use decoder::*;
 mod exclude_pattern;
 pub use exclude_pattern::*;
 
+mod dir_buffer;
+pub use dir_buffer::*;
+
 mod helper;