Add wiffi integration (#30784)

* Add integration for wiffi devices

wiffi devices are DIY board manufactured by stall.biz.
Several devices are available, e.g. a weather station (weatherman), an
indoor environmental sensor (wiffi-wz) and some more.
This intgration has been developed using a weatherman device, but should
also work for other devices from stall.biz.

* Fix pylint warning

* Use WIFFI / STALL WIFFI instead of wiffi to be consistent with stall.biz

* Don't update disabled entities.

* fix complains

- move wiffi specific code to pypi
- remove yaml configuration code

* incorporate various suggestions from code review

* fix remaining comments from Martin

* fix comments

* add tests for config flow

* fix comments

* add missing requirements for tests

* fix pylint warnings

* fix comments

* fix comments

remove debug log
rename .translations to translations

* rebase and adapt to latest dev branch

* Update homeassistant/components/wiffi/config_flow.py

Co-Authored-By: Martin Hjelmare <marhje52@gmail.com>

* Update homeassistant/components/wiffi/config_flow.py

Co-Authored-By: Martin Hjelmare <marhje52@gmail.com>

* fix missing import

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

homeassistant/components/wiffi/binary_sensor.py

@@ -0,0 +1,53 @@
+"""Binary sensor platform support for wiffi devices."""
+
+from homeassistant.components.binary_sensor import BinarySensorEntity
+from homeassistant.core import callback
+from homeassistant.helpers.dispatcher import async_dispatcher_connect
+
+from . import WiffiEntity
+from .const import CREATE_ENTITY_SIGNAL
+
+
+async def async_setup_entry(hass, config_entry, async_add_entities):
+    """Set up platform for a new integration.
+
+    Called by the HA framework after async_forward_entry_setup has been called
+    during initialization of a new integration (= wiffi).
+    """
+
+    @callback
+    def _create_entity(device, metric):
+        """Create platform specific entities."""
+        entities = []
+
+        if metric.is_bool:
+            entities.append(BoolEntity(device, metric))
+
+        async_add_entities(entities)
+
+    async_dispatcher_connect(hass, CREATE_ENTITY_SIGNAL, _create_entity)
+
+
+class BoolEntity(WiffiEntity, BinarySensorEntity):
+    """Entity for wiffi metrics which have a boolean value."""
+
+    def __init__(self, device, metric):
+        """Initialize the entity."""
+        super().__init__(device, metric)
+        self._value = metric.value
+        self.reset_expiration_date()
+
+    @property
+    def is_on(self):
+        """Return the state of the entity."""
+        return self._value
+
+    @callback
+    def _update_value_callback(self, device, metric):
+        """Update the value of the entity.
+
+        Called if a new message has been received from the wiffi device.
+        """
+        self.reset_expiration_date()
+        self._value = metric.value
+        self.async_write_ha_state()