refactor: refactoring yuque connector

[medcl]

What does this PR do

This pull request introduces several changes to the plugins/connectors/yuque package, primarily focusing on enhancing the collection and indexing of book table of contents (TOC) and improving error handling. The most important changes include the addition of a new struct BookToc, modifications to the collectBooks and collectDocs functions to handle TOC data, and the addition of a new configuration option to skip TOC indexing.

Enhancements to book TOC handling:

• plugins/connectors/yuque/book.go: Added a new struct BookToc to represent the table of contents of a book, including fields for UUID, type, title, URL, and hierarchical relationships.

Modifications to collection functions:

• plugins/connectors/yuque/collect.go: Updated the collectBooks function to fetch and process the book TOC, creating a map of folder paths for documents. Introduced a temporary struct FolderInfo for sorting purposes. [1] [2]
• plugins/connectors/yuque/collect.go: Modified the collectDocs and collectDocDetails functions to accept the TOC map and include TOC information in the document metadata. [1] [2] [3]

Error handling improvements:

• plugins/connectors/yuque/collect.go: Enhanced error handling in the get function by using errors.Errorf to provide more detailed error messages when an HTTP request fails.

New configuration option:

• plugins/connectors/yuque/plugin.go: Added a new configuration option SkipIndexingBookToc to allow users to skip the indexing of book TOC if desired.

Rationale for this change

Standards checklist

• The PR title is descriptive
• The commit messages are semantic
• Necessary tests are added
• Updated the release notes
• Necessary documents have been added if this is a new feature
• Performance tests checked, no obvious performance degradation