feat(editor): add experimental feature citation (#11984)

Closes: [BS-3122](https://linear.app/affine-design/issue/BS-3122/footnote-definition-adapter-适配)
Closes: [BS-3123](https://linear.app/affine-design/issue/BS-3123/几个-block-card-view-适配-footnote-态)

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

- **New Features**
  - Introduced a new citation card component and web element for displaying citations.
  - Added support for citation-style rendering in attachment, bookmark, and linked document blocks.
  - Enabled citation parsing from footnote definitions in markdown for attachments, bookmarks, and linked docs.
  - Added a feature flag to enable or disable citation features.
  - Provided new toolbar logic to disable downloads for citation-style attachments.

- **Improvements**
  - Updated block models and properties to support citation identifiers.
  - Added localization and settings for the citation experimental feature.
  - Enhanced markdown adapters to recognize and process citation footnotes.
  - Included new constants and styles for citation card display.

- **Bug Fixes**
  - Ensured readonly state is respected in block interactions and rendering for citation blocks.

- **Documentation**
  - Added exports and effects for new citation components and features.

- **Tests**
  - Updated snapshots to include citation-related properties in block data.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/model/src/blocks/embed/linked-doc/linked-doc-model.ts

@@ -10,11 +10,13 @@ export const EmbedLinkedDocStyles: EmbedCardStyle[] = [
   'list',
   'cube',
   'horizontalThin',
+  'citation',
 ];
 
 export type EmbedLinkedDocBlockProps = {
   style: EmbedCardStyle;
   caption: string | null;
+  footnoteIdentifier: string | null;
 } & ReferenceInfo;
 
 export class EmbedLinkedDocModel extends defineEmbedModel<EmbedLinkedDocBlockProps>(

blocksuite/affine/model/src/blocks/embed/linked-doc/linked-doc-schema.ts

@@ -14,6 +14,8 @@ const defaultEmbedLinkedDocBlockProps: EmbedLinkedDocBlockProps = {
   // title & description aliases
   title: undefined,
   description: undefined,
+
+  footnoteIdentifier: null,
 };
 
 export const EmbedLinkedDocBlockSchema = createEmbedBlockSchema({