Reorganize S3 clients

crates/pile-io/src/chacha/mod.rs

@@ -0,0 +1,9 @@
+mod reader;
+mod reader_async;
+mod writer;
+mod writer_async;
+
+pub use {reader::*, reader_async::*, writer::*, writer_async::*};
+
+mod format;
+pub use format::*;