Create a temporary account to be the fee payer when calling Wormhole

[ruuda]

When we call wormhole, we need to provide a payer account, which must sign the transaction. The Wormhole program then transfers the fee from that account. The payer in our case is the maintainer’s key.

If the Wormhole program gets upgraded, it might start taking more fee, it could suddenly steal all of the maintainer’s funds. Currently all of the maintainers have at most 2 SOL in their accounts so there is not that much to gain, but still, it would be nicer to:

• Create a new temporary throwaway account.
• Transfer just enough SOL to it to pay for the Wormhole transaction fee.
• Use that as the Wormhole fee payer, instead of the maintainer itself.