Feature/ Add option to pass custom replacement dictionaries for bias tests

[RakshitKhajuria]

Checklist:

• I've added Google style docstrings to my code.
• I've used pydantic for typing when/where necessary.
• I have linted my code
• I have added tests to cover my changes.

[Prikshit7766]

• If append is True, the custom bias data will be appended to the existing bias data.
• If append is False, the custom bias data will replace the existing bias data.