[Sept 29, 2022] Replace getContractsForOwner 'ownedCount' field with 'numDistinctTokensOwned' and 'totalBalance'

The ownedCount field of getContractsForOwner has been replaced with two new fields: totalBalance, which is the sum of all balances held on all tokens on a contract; and numDistinctTokensOwned, which is the number of distinct token IDs held. The ownedCount field (which currently holds the same data as totalBalance) is deprecated and will be removed after a few weeks.