findProgramAddress does not need to be async

[yangli-io]

Problem

findProgramAddress is an async function but nothing about it requires it to be async
This makes it harder to write programs, for example if you wanted to use it in an array map you would have to use promise.all

For example if I wanted to find all the PDA for an account I would need to do something like the below

const findAllDerivedAccounts = await Promise.all(accounts.map(async (account, index) => {
  const [PDA] = await findProgramAddress(account.toBuffer(), programId);

  return PDA; 
}))

Proposed Solution

Remove async from createProgramAddress and findProgramAddress