Update the checkpoint loader logic for inference

This PR enhanced the checkpoint loader logic of DeepEdit inference, to load weights in the initialization.

Ready

[x] Codeformat tests passed locally by running ./runtests.sh --codeformat.
[ ] In-line docstrings updated.
[ ] Update version and changelog in metadata.json if changing an existing bundle.
[ ] Please ensure the naming rules in config files meet our requirements (please refer to: CONTRIBUTING.md).
[ ] Ensure versions of packages such as monai, pytorch and numpy are correct in metadata.json.
[ ] Descriptions should be consistent with the content, such as eval_metrics of the provided weights and TorchScript modules.
[ ] Files larger than 25MB are excluded and replaced by providing download links in large_file.yml.
[ ] Avoid using path that contains personal information within config files (such as use /home/your_name/ for "bundle_root").

Project-MONAI / model-zoo