Add action to go to next/previous git diff in editor

Co-Authored-By: Kay Simmons <kay@zed.dev>

crates/language/src/buffer.rs

@@ -2286,8 +2286,10 @@ impl BufferSnapshot {
     pub fn git_diff_hunks_in_range<'a>(
         &'a self,
         query_row_range: Range<u32>,
+        reversed: bool,
     ) -> impl 'a + Iterator<Item = git::diff::DiffHunk<u32>> {
-        self.git_diff.hunks_in_range(query_row_range, self)
+        self.git_diff
+            .hunks_in_range(query_row_range, self, reversed)
     }
 
     pub fn diagnostics_in_range<'a, T, O>(