MM-14723: Add config flag for creating bots (#10795)

* MM-14723 add config flag for creating bots

* MM-14723 - update i18n to handle new config flag

* MM-14723 - change API tests to allow bots by default

* Update i18n/en.json

Co-Authored-By: andresoro <ao15@my.fsu.edu>

* MM-14723: add config flag for enabling/disabling bot creation

* undo changes to apitestlib.go to explicitly change config in each test

* add unit tests for config changes

* MM-14723 update test cases

* MM-14723 update test cases to use UpdateConfig method

api4/bot.go

@@ -36,6 +36,11 @@ func createBot(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if !*c.App.Config().ServiceSettings.CreateBotAccounts {
+		c.Err = model.NewAppError("createBot", "api.bot.create_disabled", nil, "", http.StatusForbidden)
+		return
+	}
+
 	createdBot, err := c.App.CreateBot(bot)
 	if err != nil {
 		c.Err = err