feat: Login via CLI (#298)

Fixes #210 - this isPR implements `coder login` in the case where the default user is already created.

This change adds:
- A prompt in the case where there is not an initial user that opens the server URL + requests a session token
  - This ports over some code from v1 for the `openURL` and `isWSL` functions to support opening the browser
- A `/api/v2/api-keys` endpoint that can be `POST`'d to in order to request a new api key for a user
  - This route was inspired by the v1 functionality
- A `cli-auth` route + page that shows the generated api key
- Tests for the new code + storybook for the new UI

The `/cli-auth` route, like in v1, is very minimal:

<img width="624" alt="Screen Shot 2022-02-16 at 5 05 07 PM" src="https://user-images.githubusercontent.com/88213859/154384627-78ab9841-27bf-490f-9bbe-23f8173c9e97.png">

And the terminal UX looks like this:

![2022-02-16 17 13 29](https://user-images.githubusercontent.com/88213859/154385225-509c78d7-840c-4cab-8f1e-074fede8f97e.gif)

coderd/coderd.go

@@ -36,6 +36,7 @@ func New(options *Options) http.Handler {
 		})
 		r.Post("/login", api.postLogin)
 		r.Post("/logout", api.postLogout)
+
 		// Used for setup.
 		r.Get("/user", api.user)
 		r.Post("/user", api.postUser)
@@ -44,10 +45,12 @@ func New(options *Options) http.Handler {
 				httpmw.ExtractAPIKey(options.Database, nil),
 			)
 			r.Post("/", api.postUsers)
-			r.Group(func(r chi.Router) {
+
+			r.Route("/{user}", func(r chi.Router) {
 				r.Use(httpmw.ExtractUserParam(options.Database))
-				r.Get("/{user}", api.userByName)
-				r.Get("/{user}/organizations", api.organizationsByUser)
+				r.Get("/", api.userByName)
+				r.Get("/organizations", api.organizationsByUser)
+				r.Post("/keys", api.postKeyForUser)
 			})
 		})
 		r.Route("/projects", func(r chi.Router) {