refactor: reorganize specs and adapter extensions (#10359)

### TL;DR
Refactored `SpecProvider` singleton access pattern and reorganized adapter/extension code structure.

### What changed?
- Changed `SpecProvider.getInstance()` to `SpecProvider._` for cleaner singleton access
- Moved adapter/extension code from `_common` directory to dedicated `adapters` and `extensions` folders
- Consolidated adapter extensions into a single file
- Removed unused dependencies from package.json
- Deleted unnecessary schema files
- Extracted `MobileSpecsPatches` class into the mobile patching code
- Updated all references to use the new `SpecProvider._` accessor

### How to test?
- Verify all specs are properly registered and accessible via `SpecProvider._`
- Test adapter functionality for HTML, Markdown, Notion HTML and plain text
- Check mobile-specific features and patches work correctly
- Ensure preview functionality works in both page and edgeless modes

### Why make this change?
- Improves code organization by properly separating adapters and extensions
- Simplifies singleton access pattern
- Removes unnecessary dependencies and files
- Makes the codebase more maintainable by consolidating related functionality

blocksuite/blocks/src/adapters/notion-html/block-matcher.ts

@@ -0,0 +1,34 @@
+import { AttachmentBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-attachment';
+import { BookmarkBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-bookmark';
+import { CodeBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-code';
+import { DatabaseBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-database';
+import { DividerBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-divider';
+import {
+  EmbedFigmaBlockNotionHtmlAdapterExtension,
+  EmbedGithubBlockNotionHtmlAdapterExtension,
+  EmbedLoomBlockNotionHtmlAdapterExtension,
+  EmbedYoutubeBlockNotionHtmlAdapterExtension,
+} from '@blocksuite/affine-block-embed';
+import { ImageBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-image';
+import { LatexBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-latex';
+import { ListBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-list';
+import { ParagraphBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-paragraph';
+import { RootBlockNotionHtmlAdapterExtension } from '@blocksuite/affine-block-root';
+import type { ExtensionType } from '@blocksuite/store';
+
+export const defaultBlockNotionHtmlAdapterMatchers: ExtensionType[] = [
+  ListBlockNotionHtmlAdapterExtension,
+  ParagraphBlockNotionHtmlAdapterExtension,
+  CodeBlockNotionHtmlAdapterExtension,
+  DividerBlockNotionHtmlAdapterExtension,
+  ImageBlockNotionHtmlAdapterExtension,
+  RootBlockNotionHtmlAdapterExtension,
+  BookmarkBlockNotionHtmlAdapterExtension,
+  DatabaseBlockNotionHtmlAdapterExtension,
+  LatexBlockNotionHtmlAdapterExtension,
+  EmbedYoutubeBlockNotionHtmlAdapterExtension,
+  EmbedFigmaBlockNotionHtmlAdapterExtension,
+  EmbedGithubBlockNotionHtmlAdapterExtension,
+  EmbedLoomBlockNotionHtmlAdapterExtension,
+  AttachmentBlockNotionHtmlAdapterExtension,
+];