Added pzemdc reset energy action

[KG3RK3N]

What does this implement/fix?

I've added a action to reset the energy on the pzemdc device.
Additionally I removed frequency_sensor_ & powerfactor_sensor_ because that was not used and are not documented. This sensors only available for AC devices.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): N/A

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#2700

Test Environment

• ESP32

• ESP32 IDF

• ESP8266

• RP2040

• PZEM-017

Example entry for config.yaml:

uart:
  tx_pin: D1
  rx_pin: D2
  baud_rate: 9600
  stop_bits: 2

sensor:
  - platform: pzemdc
    id: pzemdc_1
    current:
      name: "PZEM-017 Current"
    voltage:
      name: "PZEM-017 Voltage"
    power:
      name: "PZEM-017 Power"
    energy:
      name: "PZEM-017 Energy"
    update_interval: 60s

on_...:
  then:
    - pzemdc.reset_energy: pzemdc_1

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.