Fix nested unique name % (#303)

Author: TranquilMarmot

gdtoolkit/parser/gdscript.lark

@@ -263,7 +263,7 @@ _simple_lambda_stmt: single_lambda_stmt (";" single_lambda_stmt)* [";"]
 HEX.2: /-?0x[a-fA-F0-9][a-fA-F0-9_]*/
 BIN.2: /-?0b[01][01_]*/
 get_node: "$" (path | string | unique_node_path)
-!path: NAME ("/" NAME)*
+!path: NAME ("/" "%"? NAME)*
 !unique_node_path: "%" (path | REGULAR_STRING)
 array: "[" [type_cast ("," type_cast)* [trailing_comma]] "]"
 trailing_comma: ","

tests/formatter/input-output-pairs/simple_atom_expressions.in.gd

@@ -22,3 +22,4 @@ func foo():
 	var xc=%UniqueNodeName
 	var xd=%UniqueNodeName/Xyz
 	var xe=%"a/b/c"
+	var xf=%UniqueNodeName/%AnotherUniqueNodeName

tests/formatter/input-output-pairs/simple_atom_expressions.out.gd

@@ -23,3 +23,4 @@ func foo():
 	var xc = %UniqueNodeName
 	var xd = %UniqueNodeName/Xyz
 	var xe = %"a/b/c"
+	var xf = %UniqueNodeName/%AnotherUniqueNodeName

tests/valid-gd-scripts/unique_node_name.gd

@@ -4,3 +4,4 @@ func foo():
 	var x = $%UniqueNodeName
 	var y = %UniqueNodeName
 	var z = %"a/b/c"
+	var w = %UniqueNodeName/%AnotherUniqueNodeName