Change exemption to not carry chip_error reference

chip_error is a ctypes struct with a const char* pointer internally.
This cannot be pickled, so it's causing problems with the mobly
framework.

src/controller/python/chip/exceptions/__init__.py

@@ -39,21 +39,17 @@ class ChipStackException(Exception):
 
 
 class ChipStackError(ChipStackException):
-    def __init__(self, chip_error: PyChipError, msg=None):
-        self._chip_error = chip_error
-        self.msg = msg if msg else "Chip Stack Error %d" % chip_error.code
+    def __init__(self, code: int, msg=None):
+        self.code = code
+        self.msg = msg if msg else "Chip Stack Error %d" % self.code
 
     @classmethod
     def from_chip_error(cls, chip_error: PyChipError) -> ChipStackError:
-        return cls(chip_error, str(chip_error))
-
-    @property
-    def chip_error(self) -> PyChipError | None:
-        return self._chip_error
+        return cls(chip_error.code, str(chip_error))
 
     @property
     def err(self) -> int:
-        return self._chip_error.code
+        return self.code
 
     def __str__(self):
         return self.msg

src/controller/python/chip/native/__init__.py

@@ -69,7 +69,7 @@ class ErrorSDKPart(enum.IntEnum):
 class PyChipError(ctypes.Structure):
     ''' The ChipError for Python library.
 
-    We are using the following struct for passing the infomations of CHIP_ERROR between C++ and Python:
+    We are using the following struct for passing the information of CHIP_ERROR between C++ and Python:
 
     ```c
     struct PyChipError