Implements deterministic full-state greedy action selection [A, ACTION] = FULLSTATE_GREEDYACT(A, STATE, ACTIONS, REWARDS, PARAMS) Implements greedy deterministic action selection, using a Q-table indexed by the full world state and the agent's action. The action with the highest Q-value is chosen (breaking ties randomly). Requires the size of the Q-table to be cached under a field named 'qsize'. Supports discrete states and actions, with 1 action variable only. See also agent_act