Function login

login(connection, keyStore, loginOptions): Promise<SessionWithLogout>
Uses the provided keystore to log into the specified account
Parameters
- connection: Connection
  to interact with the blockchain that hosts the account
- keyStore: KeyStore
  keystore used to sign into the account. Must be tied to an auth descriptor associated with the account
- loginOptions: LoginOptions
  what account to sign into and other options
Returns Promise<SessionWithLogout>
the authorized session