Remove broken external oracle and fixed EIP-1559 gasPrice calculation

* Updated 1inch Oracle link and use multicall3 ( because this is the only contract supported on sepolia )
* Simplify EIP-1559 gasPrice calculation ( EIP-1559 removes necessity of using external oracles, just enough premium of basefee will ensure transaction being mined )
* Apply respective premium for fees ( Only applied on V6 Oracle class )
* Removed @tornado/gas-price-oracle oracle

src/index.ts

@@ -1,4 +1,3 @@
 export * from './feeOracleV4';
 export * from './feeOracleV5';
-export * from './feeOracleV6';
 export * from './tokenPriceOracle';