feat: default to TS for file extension and support ext flag in more scenarios (#25472)

Closes #11220
Currently does lint, fmt, and repl

cli/lsp/language_server.rs

@@ -1420,6 +1420,7 @@ impl Inner {
               document.content(),
               &fmt_options,
               &unstable_options,
+              None,
             )
           }
         };