feat: support multiple user profiles and hosts

[KernelDeimos]

Before this change it was not possible to use puter-cli on local instances of Puter, nad it was not possible to configure more than one Puter account. With this change, it is possible to add multiple accounts with specified hosts using the "puter login" command.

Technical Changes

• Login wizard is moved to modules/ProfileModule.js
• Added a function to modify exported API_BASE and BASE_URL symbols. They used to be constants but now they are not
• puter login now executes the login command via the shell. This was necessary so that the login command can have the full context of the shell (and all loaded modules); this makes puter <subcommand> commands more flexible and means there's only one entrypoint to commands instead of potentially two
• Some errors (specifically ones that got in my way) now have stack traces logged. Eventually all error handling should be delegated to a central handler so that changes like this can be made in one place.