fix(editor): comment style and creation issues (#13006)

#### PR Dependency Tree


* **PR #13006** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

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

## Summary by CodeRabbit

* **Style**
* Updated embedded note content to remove background color and underline
from inline comments for a cleaner appearance.

* **Bug Fixes**
* Improved comment functionality by ensuring comments are only added to
blocks without text content.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/embed/src/common/embed-note-content-styles.ts

@@ -57,6 +57,11 @@ export const embedNoteContentStyles = css`
     font-weight: 600;
   }
 
+  .affine-embed-doc-content-note-blocks inline-comment {
+    background-color: unset !important;
+    border-bottom: unset !important;
+  }
+
   .affine-embed-linked-doc-block.horizontal {
     affine-paragraph,
     affine-list {

blocksuite/affine/shared/src/services/comment-service/block-comment-manager.ts

@@ -70,7 +70,7 @@ export class BlockCommentManager extends LifeCycleWatcher {
           }
         );
         if (!selectedBlocks) return [];
-        return selectedBlocks.map(b => b.model);
+        return selectedBlocks.map(b => b.model).filter(m => !m.text);
       });
 
     const needCommentBlocks = [