feat(sidebar-avatar): Creat SidebarIndicator & Refactor Sidebar UI

* Add SidebarIndicator
* Remove BarIcon components at Character at Bar
  * It replaced by SidebarAvatar component
  * (TODO: Refactor BarIcon to UI Components & Sidebar State Flow)
* Refactor getCharImage
  * Delete unused code

BREAKING CHANGE:

src/lib/SideBars/SidebarAvatar.svelte

@@ -0,0 +1,24 @@
+<script>
+  export let src;
+  export let size = "22";
+</script>
+
+<span class="flex shrink-0 items-center justify-center">
+  {#if src}
+    <img
+      {src}
+      class="bg-skin-border sidebar-avatar rounded-full object-cover"
+      style:width={size + "px"}
+      style:height={size + "px"}
+      style:minWidth={size + "px"}
+      alt="avatar"
+    />
+  {:else}
+    <div
+      class="bg-skin-border sidebar-avatar rounded-full"
+      style:width={size + "px"}
+      style:height={size + "px"}
+      style:minWidth={size + "px"}
+    />
+  {/if}
+</span>