feat(entity): add ground base entity

[theEvilReaper]

Proposed changes

Currently, some aspects of a vmodel are defined in each model. It makes more sense to outsource them to reduce the complexity of each model.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• I have read the CONTRIBUTING.md
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[github-actions]

Test results

0 tests   0 ✅  0s ⏱️
0 suites  0 💤
0 files    0 ❌

Results for commit 9d4f970.

♻️ This comment has been updated with latest results.