Closes: [BS-3508](https://linear.app/affine-design/issue/BS-3508/google-docs复制内容到affine时自动加粗问题)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Improved detection of bold, italic, underline, and strike-through formatting in imported HTML, supporting both tags and inline CSS styles.
- Enhanced handling of inline elements containing block-level children to ensure correct formatting and structure during HTML import.
- Introduced a plugin that converts inline elements with block-level children into block elements, preserving original tag information.
- **Bug Fixes**
- Resolved issues where block-level elements nested inside inline tags could cause incorrect formatting or structure.
- **Tests**
- Added comprehensive test coverage for HTML formatting conversions and plugin behavior to ensure accuracy and reliability.
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Closes: [BS-3485](https://linear.app/affine-design/issue/BS-3485/粘贴-html-格式的内容时，紧邻着-bold-text-的普通文本会丢失空格)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved handling of spaces and whitespace in paragraphs when converting HTML with inline formatting, ensuring spaces are preserved as in the original content.
- **Tests**
- Added a new test to verify that spaces are correctly preserved in paragraphs containing bold and italic formatting during HTML conversion.
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<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Refactor**
- Streamlined and consolidated block and inline extension exports by removing multiple block-spec and inline extension arrays from public APIs.
- Reduced exported constants, types, and utility functions related to various block and embed features.
- Simplified the codebase by removing deprecated type guards, adapter extensions, and redundant extension groupings.
- **Chores**
- Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.
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donteatfriedrice