More useful logging for cli_wallet

**User Story**
As a developer, I want to have a log of the communication between the cli_wallet and a client that communicates with the cli_wallet via JSON-RPC interface (when cli_wallet is accepting RPC connections). These logs can assist in solving reported problems and debugging software problems.

**Impacts**
Describe which portion(s) of BitShares Core may be impacted by your request. Please tick at least one box.
- [ ] API (the application programming interface)
- [ ] Build (the build process or something prior to compiled code)
- [ ] CLI (the command line wallet)
- [ ] Deployment (the deployment process after building such as Docker, Travis, etc.)
- [ ] DEX (the Decentralized EXchange, market engine, etc.)
- [ ] P2P (the peer-to-peer network for transaction/block propagation)
- [ ] Performance (system or user efficiency, etc.)
- [ ] Protocol (the blockchain logic, consensus, validation, etc.)
- [ ] Security (the security of system or user data, etc.)
- [ ] UX (the User Experience)
- [ ] Other (please add below)

**Additional Context (optional)**
Add any other context about your request here.

## CORE TEAM TASK LIST
- [ ] Evaluate / Prioritize Feature Request
- [ ] Refine User Stories / Requirements
- [ ] Define Test Cases
- [ ] Design / Develop Solution
- [ ] Perform QA/Testing
- [ ] Update Documentation

The issue identifies cli_wallet and its JSON-RPC interface but names no source file or test. Start by locating the entry point that accepts RPC connections and determine the required request/response log scope, destination, and privacy behavior. Done should be defined by agreed requirements plus tests or a reproducible check showing the communication is logged.

Written by the indexing model from the issue text.