[api] Add homeassistant_services configuration option (#5178)

Author: bdraco

components/api.rst

@@ -98,6 +98,7 @@ Configuration variables:
       WiFi performance with many rapidly-changing sensors. Only use this setting when necessary.
 
 - **custom_services** (*Optional*, boolean): Enable compilation of custom API services for external components that use the C++ ``CustomAPIDevice`` class. Only needed when external components register their own services via the native API. Defaults to ``false``.
+- **homeassistant_services** (*Optional*, boolean): Enable compilation of Home Assistant service call support for external components that use the C++ ``CustomAPIDevice::call_homeassistant_service()`` or ``CustomAPIDevice::fire_homeassistant_event()`` methods. This is automatically enabled when using ``homeassistant.service`` or ``homeassistant.event`` actions, or the ``homeassistant`` platform for number or switch components. Only needs to be manually set when external components call Home Assistant services without using the built-in actions. Defaults to ``false``.
 - **homeassistant_states** (*Optional*, boolean): Enable compilation of Home Assistant state subscription support for external components that use the C++ ``CustomAPIDevice::subscribe_homeassistant_state()`` method. This is automatically enabled when using any ``homeassistant`` platform components (sensor, binary_sensor, text_sensor, switch, or number). Only needs to be manually set when external components subscribe to Home Assistant states without using the built-in components. Defaults to ``false``.
 - **reboot_timeout** (*Optional*, :ref:`config-time`): The amount of time to wait before rebooting when no
   client connects to the API. This is needed because sometimes the low level ESP functions report that