[MM-37984] Allow Desktop App to authenticate via external providers outside of the app on supported servers (#24140)

* [MM-37984] Allow Desktop App to authenticate via external providers outside of the app on supported servers

* PR feedback

* Add support for mattermost-dev protocol for development use

* Update server/channels/db/migrations/postgres/000110_create_desktop_tokens.up.sql

* Fix silly typo

* Update server/channels/db/migrations/postgres/000110_create_desktop_tokens.up.sql

* Remove storage of client token, only validate it on the client

* Update migrations

* Add concurrently create index

* Remove CONCURRENTLY for now

* Fix issue with changing history

* Remove old migration

* Use idempotent statement to drop old index

* Remove reference to old table

server/channels/api4/handlers.go

@@ -9,6 +9,8 @@ import (
 	"github.com/mattermost/gziphandler"
 
 	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
+	"github.com/mattermost/mattermost/server/v8/channels/app"
 	"github.com/mattermost/mattermost/server/v8/channels/web"
 )
 
@@ -200,6 +202,17 @@ func (api *API) APILocal(h handlerFunc) http.Handler {
 	return handler
 }
 
+func (api *API) RateLimitedHandler(apiHandler http.Handler, settings model.RateLimitSettings) http.Handler {
+	settings.SetDefaults()
+
+	rateLimiter, err := app.NewRateLimiter(&settings, []string{})
+	if err != nil {
+		mlog.Error("getRateLimitedHandler", mlog.Err(err))
+		return nil
+	}
+	return rateLimiter.RateLimitHandler(apiHandler)
+}
+
 func requireLicense(c *Context) *model.AppError {
 	if c.App.Channels().License() == nil {
 		err := model.NewAppError("", "api.license_error", nil, "", http.StatusNotImplemented)