Add Chainlink Functions example

[andrejrakic]

Let's add an example for Chainlink Functions as well. Because Functions Foundry Starter kit is not live yet, let's showcase how easy is to use Functions with Foundry. Also I suggest example with multiple responses, because it shows how to:

• Return complex Solidity data types (they usually return complex structures)
• Use JavaScript imports for more powerful computation
• Perform HTTP GET/POST requests using Functions library

Tasks:

• Add this contract example https://docs.chain.link/chainlink-functions/tutorials/abi-decoding
• Add this JavaScript file https://docs.chain.link/chainlink-functions/tutorials/abi-decoding
• Test it with Chainlink Local (pending)
• Optionally test it with pure Foundry using ffi flag

[zeuslawyer]

@andrejrakic
lets discuss this when you're back