Customizing create/unlock password for setup

[Maith8Ae]

Is your feature request related to a problem? Please describe.
Currently there is no way to use another password to unlock wallets while setup. This is a feature request is about how to customize wallet password during setup.

Describe the solution you'd like

1. Using environment variable OPENDEXD_PASSWORD. If launcher found this variable then it will abandon default password when creating/unlocking wallets.
2. Using --password-stdin option in command-line arguments. It will show an interactive question while creating/unlocking wallets which asks the user to input his own password.

Additional context

• The option name --password-stdin is borrowed from "docker login"
• If the stdin is a tty then using "interactive" mode (w/ a prompt)

$ opendex-launcher setup --password-stdin
Please enter your wallet password:

• If it's not a tty then just read it w/o any prompt.

$ cat wallet_password.txt | opendex-launcher setup --password-stdin