Fix more bugs in files (#16241)

Fixes:
- [x] an issue where directories would only match by prefix, causing
both a directory and a file to be matched if in the same directory
- [x] An issue where you could not continue a file completion when
selecting a directory, as `tab` on a file would always run the command.
This effectively disabled directory sub queries.
- [x] Inconsistent rendering of files and directories in the slash
command

Release Notes:

- N/A

---------

Co-authored-by: max <max@zed.dev>

crates/util/src/paths.rs

@@ -263,7 +263,7 @@ impl PathMatcher {
         let path_str = path.to_string_lossy();
         let separator = std::path::MAIN_SEPARATOR_STR;
         if path_str.ends_with(separator) {
-            self.glob.is_match(path)
+            return false;
         } else {
             self.glob.is_match(path_str.to_string() + separator)
         }