fix(editor): footnote popup style and position issues (#11771)

Close [BS-3049](https://linear.app/affine-design/issue/BS-3049/chat引用的样式坏了) [BS-3024](https://linear.app/affine-design/issue/BS-3024/footnote-在容器边缘时，hover-抽搐)

blocksuite/affine/shared/src/services/doc-display-meta-service.ts

@@ -217,7 +217,7 @@ export class DocDisplayMetaService
 function iconBuilder(
   icon: typeof PageIcon,
   size = '1.25em',
-  style = 'user-select:none;flex-shrink:0;vertical-align:middle;font-size:inherit;margin-bottom:0.1em;'
+  style = 'user-select:none;flex-shrink:0;vertical-align:middle;font-size:inherit;'
 ) {
   return icon({ width: size, height: size, style });
 }