* add SendTransactionWithSignature to Transactor
* add comment to SendTransactionWithSignature
* add SendTransactionWithSignature to StatusBackend
* add SendTransactionWithSignature to lib
* add SendTransactionWithSignature to mobile pkg
* increment nonce if needed
* add TestSendTransactionWithSignature_IncrementingNonce
* add NoError assertion
* validate tx args
* debug CI adding `env`
* CI debug
* remove debug
* return error if tx nonce is not the expected one
* fix lint warning
This PR does a few things:
1) Add a call GetContactCode to check whether we have a bundle for a
given user.
2) Add a DH flag to the API (non-breaking change), for those messages
that we want to target all devices (contact-requests for example).
3) Fixes a few small issues with installations, namely if for example a
messages is sent without a bundle (currently not done by any client),
we still infer installation info, so that we can communicate securely
and making it truly optional.