fix: improve callout block functionality and slash menu configuration

blocksuite/affine/blocks/callout/src/callout-block.ts

@@ -29,7 +29,7 @@ export class CalloutBlockComponent extends CaptionedBlockComponent<CalloutBlockM
     }
 
     .affine-callout-emoji-container {
-      margin-right: 10px;
+      margin-left: 6px;
       user-select: none;
       font-size: 1.2em;
       width: 24px;
@@ -37,7 +37,7 @@ export class CalloutBlockComponent extends CaptionedBlockComponent<CalloutBlockM
       display: flex;
       align-items: center;
       justify-content: center;
-      margin-top: 2px;
+      margin-top: 10px;
       flex-shrink: 0;
     }
     .affine-callout-emoji:hover {

blocksuite/affine/blocks/callout/src/configs/slash-menu.ts

@@ -1,24 +1,12 @@
-import { CalloutBlockModel } from '@blocksuite/affine-model';
 import { focusBlockEnd } from '@blocksuite/affine-shared/commands';
 import { FeatureFlagService } from '@blocksuite/affine-shared/services';
-import {
-  findAncestorModel,
-  isInsideBlockByFlavour,
-  matchModels,
-} from '@blocksuite/affine-shared/utils';
+import { isInsideBlockByFlavour } from '@blocksuite/affine-shared/utils';
 import { type SlashMenuConfig } from '@blocksuite/affine-widget-slash-menu';
 import { FontIcon } from '@blocksuite/icons/lit';
 
 import { calloutTooltip } from './tooltips';
 
 export const calloutSlashMenuConfig: SlashMenuConfig = {
-  disableWhen: ({ model }) => {
-    return (
-      findAncestorModel(model, ancestor =>
-        matchModels(ancestor, [CalloutBlockModel])
-      ) !== null
-    );
-  },
   items: [
     {
       name: 'Callout',