Improve first-time launch process

[vufon]

Upon the first launch, initializing and running dcrwallet requires significant time and effort from users.

• The configuration file is neither automatically generated nor initialized with the necessary RPC values.
• If the wallet is not created, the user must re-launch the --create command, as no solution is provided to create the wallet during the initial run.
• The naming of RPC parameters in dcrwallet remains inconsistent with those in dcrd.

• Dcrd rpc params: rpcuser - rpcpass
• Dcrwallet rpc params: username - password

• Although rpcAuthType is set to "basic," the clientCAs certificate is still checked, and a warning is issued
  "DCRW: gRPC server is configured with listeners, but no trusted client certificates exist (looked in /home/x/.dcrwallet/clients.pem)"

Although Decred provides a dcrinstall binary for quick installation and setup, there remains a need for active and comprehensive support for programs when run individually.