feat(技能图标): 添加冷却进度百分比功能并优化能量显示

为CooldownTimer添加percent方法计算冷却进度百分比
重构SkillIcon使用新的冷却进度和能量填充进度计算
添加白色圆圈SVG资源作为粒子效果
优化EntityBase的能量计算方法
更新SkillIcon场景配置

resources/common/whitecircle.svg

@@ -0,0 +1 @@
+<svg width="103" height="104" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" overflow="hidden"><g transform="translate(-551 -482)"><path d="M555 534C555 507.49 576.49 486 603 486 629.51 486 651 507.49 651 534 651 560.51 629.51 582 603 582 576.49 582 555 560.51 555 534Z" stroke="#FFFFFF" stroke-width="6" stroke-miterlimit="8" fill="none" fill-rule="evenodd"/></g></svg>

resources/common/whitecircle.svg.import

@@ -0,0 +1,43 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://bmpo06vnnywim"
+path="res://.godot/imported/whitecircle.svg-1ed5ca2d5c4f265484656a69d2464cdd.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://resources/common/whitecircle.svg"
+dest_files=["res://.godot/imported/whitecircle.svg-1ed5ca2d5c4f265484656a69d2464cdd.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/uastc_level=0
+compress/rdo_quality_loss=0.0
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/channel_remap/red=0
+process/channel_remap/green=1
+process/channel_remap/blue=2
+process/channel_remap/alpha=3
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
+svg/scale=1.0
+editor/scale_with_editor_scale=false
+editor/convert_colors_with_editor_theme=false