Allow connecting multiple accounts at once

[magico13]

Right now you can add two accounts but it'll mess up the authorization such that one will become unauthorized (using the credentials of the other one). Might require changes within PyEmVue.

Not sure if there's really any value to this since you can add multiple Vues to one account. Maybe the owner of a multi-family dwelling wants to give each tenant access to just their own but wants to be able to follow both in home assistant? If you're reading this and it's something you have a use-case for then please post a comment. Otherwise this will likely just be a thing I keep in the back of my mind with future development.