change get_balance to general get_state

[saeveritt]

Also renamed variable deck to deck_id for the ones being passed throughfind_deck()as the function uses <id>, <name>, <issuer>, <issue_mode>, <number_of_decimals> to query.

LN#293 was passing a deck object defined a few lines before it to function get_balance() which calls find_deck() that requires a non deck object input.