Add support for climate component, platform: modbus

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

Possibility to create a climate component using platform: modbus to be able to write/read directly to registry addresses or to an already defined sensor:

Example:

- name: "hp_water_climate"
      address: 1020
      register_type: holding
      value_type: S_WORD
      multiply: 10
      max_temp: 60
      min_temp: 15
      offset: 0
      precision: 1
      scale: 0.5
      temp_step: 0.5
      temperature_unit: C
      operation_modes:
          - "on"
           - "cool"
           - "heat"

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

Integrate a heatpump into homeassistant using modbus rtu and esphome

**Additional context**

Start from the requested climate component example and investigate how the existing modbus platform and climate component are organized. Identify the relevant integration points and tests, then define how registry addresses or existing sensors, temperature settings, and operation modes would be represented and verified.

Written by the indexing model from the issue text.