relax type constraints and refactor tx builder

[aleeusgr]

Currently tx's only work with Emulator, usage of API is prevented by type constraints here:

potential-robot/src/vesting-cancel.ts

Lines 20 to 24 in 7bd7935

	export const cancelVesting = async (
	network: NetworkEmulator,
	alice : WalletEmulator,
	program: Program
	) => {

Change the here and in submit tx to be WalletEulator | Wallet and NetworkEmulator | Network (something like it, see Helios docs);

test it:

• can lock with emulator
• can lock with testnet
• can cancel with emulator
• can cancel with testnet.