Python: Expand dill tests

Author: RasmusWL

python/ql/test/library-tests/frameworks/dill/Decoding.py

@@ -1,3 +1,6 @@
 import dill
 
-dill.loads(payload)  # $decodeInput=payload decodeOutput=dill.loads(..) decodeFormat=dill decodeMayExecuteInput
+dill.load(file_)  # $ MISSING: decodeInput=file_ decodeOutput=dill.loads(..) decodeFormat=dill decodeMayExecuteInput
+dill.load(file=file_)  # $ MISSING: decodeInput=file_ decodeOutput=dill.loads(..) decodeFormat=dill decodeMayExecuteInput
+dill.loads(payload)  # $ decodeInput=payload decodeOutput=dill.loads(..) decodeFormat=dill decodeMayExecuteInput
+dill.loads(str=payload)  # $ decodeOutput=dill.loads(..) decodeFormat=dill decodeMayExecuteInput MISSING: decodeInput=payload