Support RawTx Creation #7
Description
Right now, the ConnectedContract's methods directly send a transaction with the unlocked account specified in the txObj. This implies we'd have to sign each account on the node we want to use.
Ideally, the ConnectedContract proxy should be able to infer whether to generate a rawTx or directly send a Tx by checking if the txObj has specified a "from" field. If from is not specified, return a raw sendTx object to be signed outside the scope of typ3 and passed through a node. If from is specified, call eth_sendTx directly (this is the functionality we currently support).