Move auto_annotate logic into ExpertReportAnnotation model

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 95.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 45.75%. Comparing base (7aa8ee6) to head (499a853).

Files with missing lines	Patch %	Lines
tigacrafting/models.py	94.87%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #271 +/- ## ========================================== - Coverage 45.78% 45.75% -0.04% ========================================== Files 69 69 Lines 10350 10322 -28 ========================================== - Hits 4739 4723 -16 + Misses 5611 5599 -12 ```

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