vim: Implement named registers (#12895)

Release Notes:

- vim: Add support for register selection `"a`-`"z`, `"0`-`"9`, `"-`.
`"_` and `"%`
([#11511](https://github.com/zed-industries/zed/issues/11511))

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/editor/src/editor.rs

@@ -1502,7 +1502,7 @@ struct ActiveDiagnosticGroup {
     is_valid: bool,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Clone)]
 pub struct ClipboardSelection {
     pub len: usize,
     pub is_entire_line: bool,