Reset total energy on pzem004t

**Describe the problem you have/What new integration you would like**

There's no way to reset the total energy on the pzem004t integration.

**Please describe your use case for this integration and alternatives you've tried:**

It would be great for having HA/other integration to reset the total energy count once the billing cycle is over

**Additional context**

As commented here: https://github.com/esphome/feature-requests/issues/457#issuecomment-559592783
There's a way to send a command to the PZEM to reset this value. Maybe expose that as a command or switch?

Start by reviewing the PZEM004T integration and the linked feature-request comment describing the device reset command. Determine whether the billing-cycle use case should expose a command or switch, then verify that the total-energy value resets through the ESPHome and Home Assistant integration paths.

Written by the indexing model from the issue text.