Your device seems to support USB OTG functionality. Given that, you can buy an OTG cable and use a mouse (any mouse would work) to control the device, just like you control a computer using a mouse.
Once you unlock the device, attempt to root it, then install Xposed Framework for Nougat, followed by installation of GravityBox [N] Xposed module.
If you find a flash tool which allows partial flashing without data loss, you can add these lines in build.prop and flash modified system partition
Motorola uses a vanilla Android experience (similar to Android One & Pixel) and it ships with the Google dialer and Google contacts app. As such, you will not find as many options in your phone as we see in Xiaomi or Huawei or Samsung phones. The call blocking option is also not present in the stock Android setup.
You will have to resort to a 3rd party ...