surf: Add FileDiff::path method

This allows to get the latest path of a `FileDiff`, directly from
`radicle_surf`

Signed-off-by: Sebastian Martinez <me@sebastinez.dev>

radicle-surf/src/diff.rs

@@ -287,6 +287,18 @@ pub enum FileDiff {
     Copied(Copied),
 }
 
+impl FileDiff {
+    pub fn path(&self) -> &PathBuf {
+        match self {
+            FileDiff::Added(x) => &x.path,
+            FileDiff::Deleted(x) => &x.path,
+            FileDiff::Modified(x) => &x.path,
+            FileDiff::Moved(x) => &x.new_path,
+            FileDiff::Copied(x) => &x.new_path,
+        }
+    }
+}
+
 #[cfg(feature = "serde")]
 impl Serialize for FileDiff {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>