json rpc for swap tokens takes u128 as argument

[nuel77]

Both the below methods takes u128 as type for the amount.

pub trait PolkadexSwapRpcApi<BlockHash> {
	#[method(name = "tx_quotePriceExactTokensForTokens")]
	async fn quote_price_exact_tokens_for_tokens(
		&self,
		asset_id1: String,
		asset_id2: String,
		amount: u128,
		include_fee: bool,
	) -> RpcResult<Option<u128>>;

	#[method(name = "tx_quotePriceTokensForExactTokens")]
	async fn quote_price_tokens_for_exact_tokens(
		&self,
		asset_id1: String,
		asset_id2: String,
		amount: u128,
		include_fee: bool,
	) -> RpcResult<Option<u128>>;
}

Since this in ecoded as json rpc, u128 can fail deserialization for very large numbers as this is not supported in json.