Better cli support for custom lit session

[cjc21]

Is your feature request related to a problem? Please describe.
I am trying to add a specific permission to my readonly LIT account. I like that I could view my node on the go, but I want to also be able to perform low risk operations on the go too (for example update routing fees)

Describe the solution you'd like
Right now there is no straightforward way to do this via the CLI because Lit CLI doesn't take the same arguments as bakemacaroon. Lit CLI only takes URIs as arguments, and as far as I know there is no easy way to find out the URIs for a readonly macaroon.

Please read this slack thread for more context

Describe alternatives you've considered
Allow the CLI to take the same argument as bake macaroon like info:read etc.