refactor(analyzer): redefine *_analyzer into steps

- update imports and names
- define step as a protocol
- extract analyzer function from classes

analyzer/tests/steps/analyze_cuepoint_test.py

@@ -1,9 +1,11 @@
+from unittest.mock import patch
+
 import distro
 import pytest
 
-from libretime_analyzer.cuepoint_analyzer import CuePointAnalyzer
+from libretime_analyzer.steps.analyze_cuepoint import analyze_cuepoint
 
-from .fixtures import FILE_INVALID_DRM, FILES, Fixture
+from ..fixtures import FILE_INVALID_DRM, FILES, Fixture
 
 
 @pytest.mark.parametrize(
@@ -11,7 +13,7 @@ from .fixtures import FILE_INVALID_DRM, FILES, Fixture
     map(lambda i: (str(i.path), i.length, i.cuein, i.cueout), FILES),
 )
 def test_analyze(filepath, length, cuein, cueout):
-    metadata = CuePointAnalyzer.analyze(filepath, dict())
+    metadata = analyze_cuepoint(filepath, dict())
 
     assert metadata["length_seconds"] == pytest.approx(length, abs=0.1)
 
@@ -32,10 +34,11 @@ def test_analyze(filepath, length, cuein, cueout):
 
 
 def test_analyze_missing_silan():
-    old = CuePointAnalyzer.SILAN_EXECUTABLE
-    CuePointAnalyzer.SILAN_EXECUTABLE = "foobar"
-    CuePointAnalyzer.analyze(str(FILES[0].path), dict())
-    CuePointAnalyzer.SILAN_EXECUTABLE = old
+    with patch(
+        "libretime_analyzer.steps.analyze_cuepoint.SILAN_EXECUTABLE",
+        "foobar",
+    ):
+        analyze_cuepoint(str(FILES[0].path), dict())
 
 
 def test_analyze_invalid_filepath():