Better handling for arguments edge cases

[dannasessha]

z_getoperationresult and z_getoperationstatus
both have a single optional argument that is an array.

z_sendmany has an argument in its listed arguments (2.) that is an array with nested objects.

z_mergetoaddress has an argument (1.) that is an array.

We need to better handle optional arguments.

We also need to better handle array arguments.