Add ability to use arrays/structs/dictionaries as transaction arguments

[timongll]

Right now Flow Playground does not allow arrays/lists/structs to be inputs in transaction parameters. Will give the error: Error: GraphQL error: failed to decode argument 0: failed to decode value: invalid JSON Cadence structure

[deivydas321]

I can add that the same error is with dictionaries.

[bthaile]

closing, dup issue https://github.com/onflow/flow-playground/issues/649