[TASK] deprecate default network in near-cli config

[thisisjoshford]

Proposal for: [deprecate default network in near-cli]

What is this?

• near-cli currently uses default network in config.js to store credentials for testnet.
• This can cause issues when running commands without a --networkId flag pointing to testnet credential folder (If that is where your keys are located).
• create-near-app currently stores dev accounts to testnet directory and is causing some issues.
• recent issue has been filed here regarding this CLI is not able to work with .near-credentials/testnet appropriately near-cli#677
• this work would also help resolve near login ignores optional flags near-cli#394

Who needs to be involved?

• @thisisjoshford

Tasks to complete

• change default networkId to testnet in config.js
• notify users that credentials were not found in testnet and write logic to check in default
• ask user if they would like near-cli to transfer keys from default to testnet

What t-shirt size is this?

MED

What priority is this?

P1