Add HarmonyOS Sans font and implement QuickUI for text handling

- Imported HarmonyOS Sans Regular font with appropriate settings for rendering and fallback.
- Created QuickUI script to facilitate the creation of small text labels with optional centering.
- Added new theme resources for big bold text and small text, defining font sizes for RichTextLabel and Label respectively.

scripts/Tools/QuickUI.gd

@@ -0,0 +1,9 @@
+class_name QuickUI
+
+static func smallText(text: String, center: bool = true):
+	var label = Label.new()
+	label.text = text
+	label.theme = preload("res://themes/smallText.tres")
+	if center:
+		label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
+	return label