Add BaseEntity for apsystems integration (#117514)

* Add BaseEntity for apsystems integration

* Exclude entity.py from apsystems from coverage

* Remove api from BaseEntity from apsystems as it is not yet used

* Split BaseEntity and BaseCoordinatorEntity in apsystems integration

* Clean up of asserting unique_id everywhere in apsystems integration

* Remove BaseCoordinatorEntity from apsystems

* Remove double type declaration originating from merge in apsystems

homeassistant/components/apsystems/entity.py

@@ -0,0 +1,27 @@
+"""APsystems base entity."""
+
+from __future__ import annotations
+
+from homeassistant.helpers.device_registry import DeviceInfo
+from homeassistant.helpers.entity import Entity
+
+from . import ApSystemsData
+from .const import DOMAIN
+
+
+class ApSystemsEntity(Entity):
+    """Defines a base APsystems entity."""
+
+    _attr_has_entity_name = True
+
+    def __init__(
+        self,
+        data: ApSystemsData,
+    ) -> None:
+        """Initialize the APsystems entity."""
+        self._attr_device_info = DeviceInfo(
+            identifiers={(DOMAIN, data.device_id)},
+            serial_number=data.device_id,
+            manufacturer="APsystems",
+            model="EZ1-M",
+        )