Make Rflink handle set_level command for dimmable devices (#46499)

* Added handle_event for set_level command in dimmable devices

* refactor common code for dimmable devices

* Force tests

Silly change to force tests execution

* fix super()

* add rflink dim utils

tests/components/rflink/test_utils.py

@@ -0,0 +1,33 @@
+"""Test for RFLink utils methods."""
+from homeassistant.components.rflink.utils import (
+    brightness_to_rflink,
+    rflink_to_brightness,
+)
+
+
+async def test_utils(hass, monkeypatch):
+    """Test all utils methods."""
+    # test brightness_to_rflink
+    assert brightness_to_rflink(0) == 0
+    assert brightness_to_rflink(17) == 1
+    assert brightness_to_rflink(34) == 2
+    assert brightness_to_rflink(85) == 5
+    assert brightness_to_rflink(170) == 10
+    assert brightness_to_rflink(255) == 15
+
+    assert brightness_to_rflink(10) == 0
+    assert brightness_to_rflink(20) == 1
+    assert brightness_to_rflink(30) == 1
+    assert brightness_to_rflink(40) == 2
+    assert brightness_to_rflink(50) == 2
+    assert brightness_to_rflink(60) == 3
+    assert brightness_to_rflink(70) == 4
+    assert brightness_to_rflink(80) == 4
+
+    # test rflink_to_brightness
+    assert rflink_to_brightness(0) == 0
+    assert rflink_to_brightness(1) == 17
+    assert rflink_to_brightness(5) == 85
+    assert rflink_to_brightness(10) == 170
+    assert rflink_to_brightness(12) == 204
+    assert rflink_to_brightness(15) == 255