Unify if/when condition formatting

crates/compiler/test_syntax/tests/snapshots/pass/when_newline_after_condition.expr.formatted.roc

@@ -0,0 +1,5 @@
+when
+    n
+    # s
+is
+    O -> 1

crates/compiler/test_syntax/tests/snapshots/pass/when_newline_after_condition.expr.result-ast

@@ -0,0 +1,27 @@
+When(
+    @5-6 SpaceAfter(
+        Var {
+            module_name: "",
+            ident: "n",
+        },
+        [
+            Newline,
+            LineComment(
+                "s",
+            ),
+        ],
+    ),
+    [
+        WhenBranch {
+            patterns: [
+                @13-14 Tag(
+                    "O",
+                ),
+            ],
+            value: @16-17 Num(
+                "1",
+            ),
+            guard: None,
+        },
+    ],
+)

crates/compiler/test_syntax/tests/snapshots/pass/when_newline_after_condition.expr.roc

@@ -0,0 +1,3 @@
+when n
+#s
+is O->1

crates/compiler/test_syntax/tests/test_snapshots.rs

@@ -657,6 +657,7 @@ mod test_snapshots {
         pass/when_in_function_python_style_indent.expr,
         pass/when_in_parens.expr,
         pass/when_in_parens_indented.expr,
+        pass/when_newline_after_condition.expr,
         pass/when_result_list.expr,
         pass/when_with_alternative_patterns.expr,
         pass/when_with_function_application.expr,