clipboard: persist clipboard contents after source application closes

When the source application closes, the forked child continues serving
clipboard data so it remains available for paste operations.

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I14fbcf8cbc47c40bfa1da7f8b09245936a6a6964

src/clipboard/mod.rs

@@ -0,0 +1,3 @@
+pub mod persist;
+
+pub use persist::{ClipboardData, get_serving_pid, persist_clipboard};