[MM-57942] Fix a panic on password is too long (#27449)

* return error from bcrypt, handle gracefully; remove dead code

* linting

* linting

* i18n

* fix test

* fill out translations

server/channels/app/user.go

@@ -1445,7 +1445,11 @@ func (a *App) UpdatePassword(rctx request.CTX, user *model.User, newPassword str
 		return model.NewAppError("UpdatePassword", "api.user.update_password.failed.app_error", nil, "", http.StatusInternalServerError)
 	}
 
-	hashedPassword := model.HashPassword(newPassword)
+	hashedPassword, err := model.HashPassword(newPassword)
+	if err != nil {
+		// can't be password length (checked in IsPasswordValid)
+		return model.NewAppError("UpdatePassword", "api.user.update_password.password_hash.app_error", nil, "user_id="+user.Id, http.StatusInternalServerError).Wrap(err)
+	}
 
 	if err := a.Srv().Store().User().UpdatePassword(user.Id, hashedPassword); err != nil {
 		return model.NewAppError("UpdatePassword", "api.user.update_password.failed.app_error", nil, "", http.StatusInternalServerError).Wrap(err)