[hlw8012]: new counter impl

[mknjc]

What does this implement/fix?

Replace the pulse counter with a specialized implementation.
The old implementation had worse resolution with low loads and fast update intervals.
Additionally, jitter in the update interval, caused by other components doesn't cause measurement errors anymore.
The new implementation reduces flash usage as long as the pulse counter isn't used somewhere else.

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): -

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

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040
• BK72xx
• RTL87xx
  Tested with a BL0937

Example entry for config.yaml:

sensor:
  - platform: hlw8012
    model: BL0937
    sel_pin: GPIO12
    cf_pin: GPIO04
    cf1_pin: GPIO05
    change_mode_every: 4
    current_resistor: 0.001
    voltage_divider: 1700
    update_interval: 3s

    current:
      name: "Test - Ampere"
      unit_of_measurement: A
      accuracy_decimals: 3
      icon: mdi:current-ac

    voltage:
      name: "Test - Volt"
      unit_of_measurement: V
      accuracy_decimals: 1
      icon: mdi:flash-outline

    power:
      name: "Test - Watt"
      unit_of_measurement: W
      id: "power_wattage"
      icon: mdi:gauge

    energy:
      name: "Test - Energy"

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.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 54.25%. Comparing base (4d8b5ed) to head (28ecb72).
Report is 572 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #6730      +/-   ##
==========================================
+ Coverage   53.70%   54.25%   +0.54%     
==========================================
  Files          50       50              
  Lines        9408     9587     +179     
  Branches     1654     1689      +35     
==========================================
+ Hits         5053     5201     +148     
- Misses       4056     4062       +6     
- Partials      299      324      +25     

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