feat: Enhance game mechanics and structure

- Added `ColorBar` class for visual representation of values.
- Expanded `EntityBase` with new properties: `isBoss` and `weapons`, and implemented damage handling and entity generation methods.
- Updated `EntityStateBar` to use `ColorBar` for health representation.
- Introduced `BulletBase` scene and script for bullet mechanics, including damage handling and generation.
- Created `WorldTool` for managing the game world and root node.
- Implemented `EntityTool` for retrieving entities from hurtboxes.
- Added `GameRule` for managing game rules like friendly fire.
- Updated scene files to reflect new structures and added necessary resources.

scripts/Tools/WorldTool.gd

@@ -0,0 +1,9 @@
+extends Node2D
+class_name WorldTool
+
+static var rootNode: Node2D
+static var tree: SceneTree
+
+func _ready():
+    tree = get_tree()
+    rootNode = self