[MM-15490] Rework default password requirements (#10844)

* Rework default password requirements

* Update API Test Lib Default User PW

* Remove unused function; Disable password reqs in dev mode

* Disable strict password requirements for unit tests

* Update unit tests

app/authentication.go

@@ -37,6 +37,11 @@ func (tl TokenLocation) String() string {
 }
 
 func (a *App) IsPasswordValid(password string) *model.AppError {
+
+	if *a.Config().ServiceSettings.EnableDeveloper {
+		return nil
+	}
+
 	return utils.IsPasswordValidWithSettings(password, &a.Config().PasswordSettings)
 }