Lib: Add support to get tokens by chain ID

[ncomerci]

Usage example:

import { Tokens } from '@mimicprotocol/lib-ts'

import { inputs } from './types'

export default function main(): void {
  const sourceChain = inputs.sourceChain
  const destinationChain = inputs.destinationChain

  const tokenIn = Tokens.USDC.on(sourceChain)
  const tokenOut = Tokens.USDC.on(destinationChain)

  // ...
}

TODO:

• update deployment process docs

[alavarello]

Can we add some tests for this class, you can test one of the static functions.

I know that you added some examples in the comments but it's also good to know how it should be use