Move enum mapper to own file to prevent circular dependency (#90890)

* Move enum_mapper to own file to prevent circular dependency

* Add enum mapper test

tests/components/esphome/test_enum_mapper.py

@@ -0,0 +1,42 @@
+"""Test ESPHome enum mapper."""
+
+from aioesphomeapi import APIIntEnum
+
+from homeassistant.backports.enum import StrEnum
+from homeassistant.components.esphome.enum_mapper import EsphomeEnumMapper
+
+
+class MockEnum(APIIntEnum):
+    """Mock enum."""
+
+    ESPHOME_FOO = 1
+    ESPHOME_BAR = 2
+
+
+class MockStrEnum(StrEnum):
+    """Mock enum."""
+
+    HA_FOO = "foo"
+    HA_BAR = "bar"
+
+
+MOCK_MAPPING: EsphomeEnumMapper[MockEnum, MockStrEnum] = EsphomeEnumMapper(
+    {
+        MockEnum.ESPHOME_FOO: MockStrEnum.HA_FOO,
+        MockEnum.ESPHOME_BAR: MockStrEnum.HA_BAR,
+    }
+)
+
+
+async def test_map_esphome_to_ha() -> None:
+    """Test mapping from ESPHome to HA."""
+
+    assert MOCK_MAPPING.from_esphome(MockEnum.ESPHOME_FOO) == MockStrEnum.HA_FOO
+    assert MOCK_MAPPING.from_esphome(MockEnum.ESPHOME_BAR) == MockStrEnum.HA_BAR
+
+
+async def test_map_ha_to_esphome() -> None:
+    """Test mapping from HA to ESPHome."""
+
+    assert MOCK_MAPPING.from_hass(MockStrEnum.HA_FOO) == MockEnum.ESPHOME_FOO
+    assert MOCK_MAPPING.from_hass(MockStrEnum.HA_BAR) == MockEnum.ESPHOME_BAR