- allow extracting the http client from web api transport
- refactor most commands so that they can accept an external transport
- update confirmer to use transport's http client
- update remove command
- update TwoFactorClient so it doesn't need to be mutable
- update get_server_time so it requires a transport
- update remove_authenticator
- update login proceedure to use given transport
- update usages of do_login
- update setup
- update trade
- update code command
- update qr-login command
- make borrowcheck happy
- make WebApiTransport Clone and remove Default impl
- remove dead code
- fix lints
closes#177
- clean up dead code
- fix lints
- move Session type to legacy module
- refactor service names into constants
- refactor build_url to be less restrictive for service names
- refactor most commands into their own modules
