Add dozens of new integration tests to the GDScript test suite

This also ignores `.out` files in the file format static checks.

modules/gdscript/tests/scripts/parser/features/for_range.gd

@@ -0,0 +1,39 @@
+func test():
+	for i in range(5):
+		print(i)
+
+	print()
+
+	# Equivalent to the above `for` loop:
+	for i in 5:
+		print(i)
+
+	print()
+
+	for i in range(1, 5):
+		print(i)
+
+	print()
+
+	for i in range(1, -5, -1):
+		print(i)
+
+	print()
+
+	for i in [2, 4, 6, -8]:
+		print(i)
+
+	print()
+
+	for i in [true, false]:
+		print(i)
+
+	print()
+
+	for i in [Vector2i(10, 20), Vector2i(-30, -40)]:
+		print(i)
+
+	print()
+
+	for i in "Hello_Unicôde_world!_🦄":
+		print(i)