editor: In OpenFile check if file with path_suffix exists (#17805)

Demo:


https://github.com/user-attachments/assets/6acb6c1e-bb15-4205-9dcb-2aa4bb99dcf9



Release Notes:

- When using `OpenFile` (`gf` in Vim mode) and the word under the cursor
is not an existing file path, we now fall back and additionally check
whether a file called
`<word-under-cursor>.<language-specific-path-suffixes>` exists. That's
similar to Vim's `suffixesadd` option.

---------

Co-authored-by: Abdelhakim Qbaich <abdelhakim@qbaich.com>
Co-authored-by: Pete LeVasseur <plevasseur@gmail.com>

crates/language/src/language.rs

@@ -1410,6 +1410,10 @@ impl Language {
 }
 
 impl LanguageScope {
+    pub fn path_suffixes(&self) -> &[String] {
+        &self.language.path_suffixes()
+    }
+
     pub fn language_name(&self) -> LanguageName {
         self.language.config.name.clone()
     }