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/gpui/src/keymap/context.rs

@@ -356,7 +356,7 @@ fn is_identifier_char(c: char) -> bool {
 }
 
 fn is_vim_operator_char(c: char) -> bool {
-    c == '>' || c == '<' || c == '~'
+    c == '>' || c == '<' || c == '~' || c == '"'
 }
 
 fn skip_whitespace(source: &str) -> &str {