Add new field to avoid filter code field.

[spacedmonkey]

Summary

A hotfix for WordPress 5.5-beta1.

Avoid filtering wp_get_original_image_url and wp_get_original_image_path by adding new fields.

Fixes #173

Checklist

• [ ] My pull request is addressing an open issue (please create one otherwise).
• [ ] My code is tested and passes existing tests.
• [ ] My code follows the Contributing Guidelines (updates are often made to the guidelines, check it out periodically).

[ravichdev]

@spacedmonkey This works well for the Media selectors and the Media Library, but doesn't show the correct Original URL and Unsplash name in the singe attachment edit page (accessed in Media Library list mode). We can add the filters conditionally only for this page when the post_type is attachment and it wouldn't impact the cropping feature in the single attachment edit.

[spacedmonkey]

I will approve once e2e tests pass.