avm.getUTXOs:params.addresses: A list of X-Chain addresses to fetch UTXOs for.params.limit: Optional maximum number of UTXOs to return. Defaults to 1024 if omitted or exceeded.params.startIndex: Pagination index from the previous response’s endIndex.params.sourceChain: Optional source chain ID (e.g., “P” or “C”). Used when fetching atomic UTXOs.params.encoding: Encoding format for the returned UTXOs. Must be “hex” if specified.