Refactor build_green_tree function to reduce argument count

[coderabbitai]

Problem

The build_green_tree function currently has too many arguments (7 parameters), triggering a clippy warning that requires suppression with #[expect(clippy::too_many_arguments)].

Current Signature

fn build_green_tree(
    tokens: Vec<(SyntaxKind, Span)>,
    src: &str,
    imports: &[Span],
    typedefs: &[Span], 
    relations: &[Span],
    indexes: &[Span],
    functions: &[Span],
    rules: &[Span],
) -> GreenNode

Proposed Solution

Group the related span parameters into a meaningful struct:

struct ParsedSpans {
    imports: Vec<Span>,
    typedefs: Vec<Span>,
    relations: Vec<Span>,
    indexes: Vec<Span>,
    functions: Vec<Span>,
    rules: Vec<Span>,
}

fn build_green_tree(
    tokens: Vec<(SyntaxKind, Span)>,
    src: &str,
    spans: &ParsedSpans,
) -> GreenNode

This approach:

• Reduces function arguments from 8 to 3
• Groups related parameters meaningfully
• Eliminates the need for clippy warning suppression
• Follows better coding practices for parameter management

Implementation Notes

• Update all calls to build_green_tree to use the new struct
• Update parse_tokens function to return the struct instead of a tuple
• Ensure all span-related operations work with the new structure

References

• PR: Implement function parser #40
• Comment: Implement function parser #40 (comment)