[services/wallet] Several changes in API after feedback
- Timestamp from block header stored in blocks table and added to each transfers
- From field is computed from signature to offload this computation from client side
- `history` event is added back, so that client can ignore historical blocks when watching
only for new blocks
- block number and timestamp are marshalled in hex. consistent with ethereum data structures
* Implement subscriptions and filtering
* Add e2e test with log filter polling logs from EVM with clique backend
* Apply review comments
* Move devnode to t/devtests to avoid cycle in imports
Dmitry Shulyak
Ivan Daniluk