Replace vcr-py for tests

[markbader]

Description:

• This PR should remove vcr-py and introduce a proxy server that replays API requests for the tests.

Todos:

Make sure to delete unnecessary points or to check all before merging:

• Updated Changelog

Fixing tests:

• Add annotation to local wk instance (e.g. tests/test_annotation.py::test_annotation_from_url)
• Zarr Streaming doesn't seem to work for local wk instance(e.g. tests/test_annotation.py::test_bounding_box_roundtrip)
• Remove date-strings from datasets generated within tests (e.g. tests/test_examples.py::test_upload_image_data)
• Replaying responses for tests/dataset/test_dataset_add_remote_mag_and_layer.py does not work yet.