chore: move /gitauth to /externalauth on the frontend (#9954)

* chore: move `/gitauth` to `/externalauth` on the frontend

This actually took a lot more jank than anticipated,
so I wanted to split this up before adding the ability
to embed new providers.

* Rename FE

* Fix em' up

* Fix linting error

* Fix e2e tests

* chore: update helm golden files

codersdk/externalauth.go

@@ -0,0 +1,90 @@
+package codersdk
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+type ExternalAuth struct {
+	Authenticated bool   `json:"authenticated"`
+	Device        bool   `json:"device"`
+	Type          string `json:"type"`
+
+	// User is the user that authenticated with the provider.
+	User *ExternalAuthUser `json:"user"`
+	// AppInstallable is true if the request for app installs was successful.
+	AppInstallable bool `json:"app_installable"`
+	// AppInstallations are the installations that the user has access to.
+	AppInstallations []ExternalAuthAppInstallation `json:"installations"`
+	// AppInstallURL is the URL to install the app.
+	AppInstallURL string `json:"app_install_url"`
+}
+
+type ExternalAuthAppInstallation struct {
+	ID           int              `json:"id"`
+	Account      ExternalAuthUser `json:"account"`
+	ConfigureURL string           `json:"configure_url"`
+}
+
+type ExternalAuthUser struct {
+	Login      string `json:"login"`
+	AvatarURL  string `json:"avatar_url"`
+	ProfileURL string `json:"profile_url"`
+	Name       string `json:"name"`
+}
+
+// ExternalAuthDevice is the response from the device authorization endpoint.
+// See: https://tools.ietf.org/html/rfc8628#section-3.2
+type ExternalAuthDevice struct {
+	DeviceCode      string `json:"device_code"`
+	UserCode        string `json:"user_code"`
+	VerificationURI string `json:"verification_uri"`
+	ExpiresIn       int    `json:"expires_in"`
+	Interval        int    `json:"interval"`
+}
+
+type ExternalAuthDeviceExchange struct {
+	DeviceCode string `json:"device_code"`
+}
+
+func (c *Client) ExternalAuthDeviceByID(ctx context.Context, provider string) (ExternalAuthDevice, error) {
+	res, err := c.Request(ctx, http.MethodGet, fmt.Sprintf("/api/v2/externalauth/%s/device", provider), nil)
+	if err != nil {
+		return ExternalAuthDevice{}, err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		return ExternalAuthDevice{}, ReadBodyAsError(res)
+	}
+	var extAuth ExternalAuthDevice
+	return extAuth, json.NewDecoder(res.Body).Decode(&extAuth)
+}
+
+// ExchangeGitAuth exchanges a device code for an external auth token.
+func (c *Client) ExternalAuthDeviceExchange(ctx context.Context, provider string, req ExternalAuthDeviceExchange) error {
+	res, err := c.Request(ctx, http.MethodPost, fmt.Sprintf("/api/v2/externalauth/%s/device", provider), req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusNoContent {
+		return ReadBodyAsError(res)
+	}
+	return nil
+}
+
+// ExternalAuthByID returns the external auth for the given provider by ID.
+func (c *Client) ExternalAuthByID(ctx context.Context, provider string) (ExternalAuth, error) {
+	res, err := c.Request(ctx, http.MethodGet, fmt.Sprintf("/api/v2/externalauth/%s", provider), nil)
+	if err != nil {
+		return ExternalAuth{}, err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		return ExternalAuth{}, ReadBodyAsError(res)
+	}
+	var extAuth ExternalAuth
+	return extAuth, json.NewDecoder(res.Body).Decode(&extAuth)
+}