fix(editor): fix color of the circle on loading icon (#12092)

* Unified loading icon
* Removed loading icon on image block
* Fixed color of circle on loading icon

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Icons in image fallback and loading states now automatically adapt to the current theme (light or dark mode) for a more consistent visual experience.

- **Style**
  - Updated loading, success, and error icons to support theming and improved their color assignments for better visibility in different themes.

- **Refactor**
  - Replaced static icon usage across several components with dynamic, theme-aware icons to ensure consistent appearance throughout the app.
  - Removed static SVG icon exports and replaced them with theme-aware icon functions for improved maintainability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/blocksuite/ai/blocks/ai-chat-block/components/chat-images.ts

@@ -1,4 +1,4 @@
-import { LoadingIcon } from '@blocksuite/affine/blocks/image';
+import { LightLoadingIcon } from '@blocksuite/affine/components/icons';
 import { css, html, LitElement, nothing } from 'lit';
 import { property } from 'lit/decorators.js';
 import { choose } from 'lit/directives/choose.js';
@@ -35,7 +35,7 @@ export class ChatImage extends LitElement {
         () =>
           html`<image-placeholder
             .text=${'Loading image'}
-            .icon=${LoadingIcon}
+            .icon=${LightLoadingIcon}
           ></image-placeholder>`,
       ],
       [

packages/frontend/core/src/blocksuite/ai/components/ai-chat-chips/utils.ts

@@ -1,4 +1,4 @@
-import { LoadingIcon } from '@blocksuite/affine/blocks/image';
+import { LightLoadingIcon } from '@blocksuite/affine/components/icons';
 import { WarningIcon } from '@blocksuite/icons/lit';
 import { type TemplateResult } from 'lit';
 
@@ -41,7 +41,7 @@ export function getChipIcon(
     return WarningIcon();
   }
   if (isLoading) {
-    return LoadingIcon;
+    return LightLoadingIcon;
   }
   return icon;
 }