Adding a pause/stop action to the integration sensor

**Describe the problem you have/What new integration you would like**
I would like the ability to stop/pause the integration sensor without resetting it.

**Please describe your use case for this integration and alternatives you've tried:**
This would give me the ability to measure the amount of volume that passed through a flow meter during a set amount of time controlled with an automation. In my case I would be using it to measuring the liquid pumped through an espresso machine.

**Additional context**