Fix `afterExecute` Hook Regression

[chris-de-leon-cll]

This PR fixes a regression introduced by https://github.com/smartcontractkit/chainlink-starknet/pull/443 where the afterExecute hook incorrectly returns void as opposed to the actual result of calling the hook. To fix the regression the following changes have been made:

• If exactly one address is passed in, the afterExecute hook is called on the address and the result is returned as-is. void is no longer returned.
• If more than one address is passed in:
  • The afterExecute hook is called on each address
  • Each invocation is performed in serial
  • The order that each invocation is performed in corresponds to the address input ordering
  • The results of each invocation are consolidated into a list and returned to the caller (the ordering of the results in the array corresponds to the order in which the input addresses were provided)