Add formatter support for call and class definition Arguments (#6274)

## Summary

This PR leverages the `Arguments` AST node introduced in #6259 in the
formatter, which ensures that we correctly handle trailing comments in
calls, like:

```python
f(
  1,
  # comment
)

pass
```

(Previously, this was treated as a leading comment on `pass`.)

This also allows us to unify the argument handling across calls and
class definitions.

## Test Plan

A bunch of new fixture tests, plus improved Black compatibility.

crates/ruff_python_ast/src/node.rs

@@ -2627,6 +2627,34 @@ impl AstNode for Comprehension {
         AnyNode::from(self)
     }
 }
+impl AstNode for Arguments {
+    fn cast(kind: AnyNode) -> Option<Self>
+    where
+        Self: Sized,
+    {
+        if let AnyNode::Arguments(node) = kind {
+            Some(node)
+        } else {
+            None
+        }
+    }
+
+    fn cast_ref(kind: AnyNodeRef) -> Option<&Self> {
+        if let AnyNodeRef::Arguments(node) = kind {
+            Some(node)
+        } else {
+            None
+        }
+    }
+
+    fn as_any_node_ref(&self) -> AnyNodeRef {
+        AnyNodeRef::from(self)
+    }
+
+    fn into_any_node(self) -> AnyNode {
+        AnyNode::from(self)
+    }
+}
 impl AstNode for Parameters {
     fn cast(kind: AnyNode) -> Option<Self>
     where
@@ -3458,6 +3486,11 @@ impl From<Comprehension> for AnyNode {
         AnyNode::Comprehension(node)
     }
 }
+impl From<Arguments> for AnyNode {
+    fn from(node: Arguments) -> Self {
+        AnyNode::Arguments(node)
+    }
+}
 impl From<Parameters> for AnyNode {
     fn from(node: Parameters) -> Self {
         AnyNode::Parameters(node)
@@ -4909,6 +4942,11 @@ impl<'a> From<&'a Comprehension> for AnyNodeRef<'a> {
         AnyNodeRef::Comprehension(node)
     }
 }
+impl<'a> From<&'a Arguments> for AnyNodeRef<'a> {
+    fn from(node: &'a Arguments) -> Self {
+        AnyNodeRef::Arguments(node)
+    }
+}
 impl<'a> From<&'a Parameters> for AnyNodeRef<'a> {
     fn from(node: &'a Parameters) -> Self {
         AnyNodeRef::Parameters(node)