Function parse_key_info 

pub fn parse_key_info(
    key_info_node: Node<'_, '_>,
) -> Result<KeyInfo, ParseError>

Parse <ds:KeyInfo> and dispatch supported child sources.

Supported source elements:

• <ds:KeyName>
• <ds:KeyValue> (dispatch by child QName; only dsig11:ECKeyValue is treated as supported EC)
• <ds:X509Data>
• <dsig11:DEREncodedKeyValue>

Unknown top-level <KeyInfo> children are ignored (lax processing), while unknown XMLDSig-owned (ds:* / dsig11:*) children inside <X509Data> are rejected fail-closed. <X509Data> may still be empty or contain only non-XMLDSig extension children.