Allow "primary" wallet recovery

[pinheadmz]

A lot of users accidentally use the primary wallet via CLI without realizing it, and it becomes very difficult to use in Bob. I propose, simply:

When user creates new wallet, if the name they provide is "primary", just prompt for a passphrase like usual and encrypt the existing primary wallet, don't throw an error and don't create a new wallet. Proceed with the default primary wallet from hsd as new "primary" wallet in Bob