fix: bless-crawl skip serializing/deserializing none fields

[zees-dev]

Description

This pull request enhances the serialization of multiple structs in src/bless_crawl/mod.rs by adding the #[serde(skip_serializing_if = "Option::is_none")] attribute to optional fields.
This change ensures that None values are excluded from serialized output, reducing payload size and improving efficiency.

Serialization Enhancements:

• ScrapeOptions struct: Added #[serde(skip_serializing_if = "Option::is_none")] to optional fields like include_tags, exclude_tags, viewport, user_agent, and headers.
• Viewport, MapOptions, and CrawlOptions structs: Applied the same attribute to optional fields such as width, height, link_types, base_url, limit, max_depth, and others.
• PageMetadata struct: Enhanced serialization by adding the attribute to a comprehensive list of optional metadata fields, including title, description, language, keywords, og_*, twitter_*, and more.
• Response struct: Added the attribute to the error field to exclude it from serialization when None.
• CrawlData struct: Applied the attribute to the link_map field for more efficient serialization.…etadata, Response, and CrawlData structs

• Introduced new optional fields with serde serialization conditions to enhance flexibility in data handling.
• Updated ScrapeOptions, MapOptions, CrawlOptions, PageMetadata, Response, and CrawlData to include additional metadata and configuration options.

[Copilot]

Pull Request Overview

This PR enhances the serialization logic in the bless_crawl module by adding the #[serde(skip_serializing_if = "Option::is_none")] attribute to various optional fields, ensuring that None values are omitted from the output.

• Serialization attributes added to optional fields in ScrapeOptions, MapOptions, CrawlOptions, PageMetadata, Response, and CrawlData.
• This change reduces payload size and may improve serialization efficiency.