Function parse_wp_type 

pub fn parse_wp_type(s: &str) -> Result<WpDataType, WpArrowError>

Parses a WPL type string into a WpDataType.

Supported formats:

• Basic types: "chars", "digit", "float", "bool", "time", "ip", "hex"
• Array types: "array<chars>", "array<array<digit>>"

Type names are case-insensitive.