Function normalize_string_value 

pub fn normalize_string_value(
    value: &str,
    is_attr: bool,
    raise_on_error: bool,
) -> Result<String, XPathError>

Normalize a string value with entity reference handling.

Handles standard XML entity references:

• < -> <
• > -> >
• & -> &
• " -> "
• ' -> '
• &#xNN; -> character by hex code
• &#NN; -> character by decimal code

Arguments

• value - The string to normalize
• is_attr - Whether this is an attribute value (applies additional normalization)
• raise_on_error - Whether to raise an error on invalid entity references

Returns

The normalized string, or an error for invalid entity references.