fix(imports): missing import for addAccessors

[sedghi]

For some reason (probably a force push) the imports for https://github.com/dcmjs-org/dcmjs/pull/274 was missing. I'm pretty sure I checked the PR and either was working for me or I fixed and pushed or not pushed. This is a fix for the missing import

[sedghi]

@pieper I'm merging this as it was breaking the whole library

[github-actions[bot]]

:tada: This PR is included in version 0.24.5 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[pieper]

Thanks @sedghi 👍