STY: Use casefold() instead of lower() (#3026)

Also add InteractiveFormDictEntries to PDF_KEYS.

Author: j-t-1

pypdf/constants.py

@@ -694,12 +694,13 @@ class AnnotationFlag(IntFlag):
     DocumentInformationAttributes,
     EncryptionDictAttributes,
     FieldDictionaryAttributes,
+    FileSpecificationDictionaryEntries,
     FilterTypeAbbreviations,
     FilterTypes,
     GoToActionArguments,
     GraphicsStateParameters,
     ImageAttributes,
-    FileSpecificationDictionaryEntries,
+    InteractiveFormDictEntries,
     LzwFilterParameters,
     PageAttributes,
     PageLayouts,

tests/test_constants.py

@@ -30,11 +30,12 @@ def test_slash_prefix():
                 continue
 
             assert constant_value.startswith("/")
-            assert attr.replace("_", "").lower() == constant_value[1:].lower()
+            assert attr.replace("_", "").casefold() == constant_value[1:].casefold()
 
             # There are a few exceptions that may be lowercase
             if cls == GraphicsStateParameters and attr in ["ca", "op"]:
                 continue
+
             assert pattern.match(constant_value)