Parse error for some valid procedural attribute macros, derive macro helper attributes

[ninevra]

tree-sitter-rust parses attributes using the meta-item syntax, which is the syntax used by most of rust's built-in attributes. The meta-item syntax is a subset of the attr syntax. Procedural attribute macros, however, use a larger subset of the attr syntax allowing arbitrary DelimTokenTrees. Derive macro helper attributes use the full attr syntax. As a result, tree-sitter-rust incorrectly parses many valid attributes.

As an example, the following is one of the usage examples for the thiserror crate. thiserror defines a derive macro helper attribute, error:

#[derive(Error, Debug)]
pub enum Error {
    #[error("first letter must be lowercase but was {:?}", first_char(.0))]
    WrongCase(String),
    #[error("invalid index {idx}, expected at least {} and at most {}", .limits.lo, .limits.hi)]
    OutOfBounds { idx: usize, limits: Limits },
} 

The phrases .limits.lo, .limits.hi, and first_char(.0) are legal under the attr syntax but not under meta-item, and so these attributes are parsed incorrectly.

This is likely the cause of atom/atom#20897. Any attribute not conforming to meta-item currently breaks atom's rust syntax highlighting.

Attributes should instead be parsed using the more permissive attr syntax.