feat: Move key annotation and entity interfaces into a new model module

[bdferris-v2]

This will allow us to break up some potential circular dependencies with upcoming support for notice documentation generation, as discussed in #1324 and #1361.

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[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1423 sources (~0 %) are corrupted.
Commit: 4a1d7a5
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[bdferris-v2]

Now wondering if this should have been core/model instead. I could see an argument for splitting up core into other submodules, such as core/io or core/notices.

[davidgamez]

Now wondering if this should have been core/model instead. I could see an argument for splitting up core into other submodules, such as core/io or core/notices.

We can always start with this simple approach(just model) and refactor in the future adding the model back to the core as core/model and the other core children.

[bdferris-v2]

Fair enough.

[davidgamez]

LGTM 🚀

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1423 sources (~0 %) are corrupted.
Commit: 0602954
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.