New clippy::cargo-toml lint category

What it does

Lints the Cargo.toml manifest file and make sure everything is alright.

Lints

• Cargo.toml — file is missing.
• Cargo.toml — file is misnamed, maybe "cargo.toml or "CARGO.toml", etc
• package.name — contains characters not allowed
• package.version — does not follow semantic versioning
• package.authors — at least one author required
• package.edition — is unknown
• package.documentation — is http not https
• package.readme — file no found
• package.homepage — is http not https
• package.repository — is http not https
• package.license — is not a SPDX 2.1 license expression
• package.license-file — file not found
• package.keywords — contains invalid letters
• package.keywords — exceeds 5 keywords
• package.categories — exceed 5 categories
• package.categories — the category does not exist
• package.build — file not found
• package.foo — unknown field
• features — feature name starts with "use-", "using-" or "with-"
• chapters are in the wrong order
• fields are in the wrong order
• dependencies are not sorted alphabetically

https://doc.rust-lang.org/cargo/reference/manifest.html

The issue names no repository files or tests. Start with the linked Cargo manifest reference, then narrow the proposed checks into an agreed scope for the new lint category. Done should mean the selected manifest validations, including their diagnostics and coverage, are clearly defined and implemented.