Remove calls to Textract from prettyprinter tests

Tests for prettyprinter call Textract directly instead of using JSON

```
def test_pretty_with_tables():
features = [Textract_Features.FORMS, Textract_Features.TABLES]
textract_client = boto3.client('textract', region_name='us-east-2')

response = call_textract(input_document="s3://amazon-textract-public-content/blogs/w2-example.png",
features=features,
boto3_textract_client=textract_client)
assert response
tables_result = get_tables_string(textract_json=response)
assert len(tables_result) > 0

response = call_textract(input_document="s3://amazon-textract-public-content/blogs/employmentapp.png",
features=features,
boto3_textract_client=textract_client)
assert response
tables_result = get_tables_string(textract_json=response)
assert len(tables_result) > 0
```

remove those calls and replace with JSON.