feat(policy-templates): add Textract policies

[timoschilling]

Issue #, if available:

Description of changes:

Adding a policy TextractPolicy that grants full access to Textract. It grants the following permissions:

• textract:*

Adding a policy TextractDetectAnalyzePolicy that grants detect and analyze access to Textract. It grants the following permissions:

• textract:DetectDocumentText
• textract:StartDocumentTextDetection
• textract:StartDocumentAnalysis
• textract:AnalyzeDocument

Adding a policy TextractDetectAnalyzePolicy that grants get result access to Textract. It grants the following permissions:

• textract:GetDocumentTextDetection
• textract:GetDocumentAnalysis

Description of how you validated changes:

I ran make pr.

Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Add/update example to examples/2016-10-31

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-io]

Codecov Report

Merging #1377 into develop will decrease coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           develop   #1377      +/-   ##
==========================================
- Coverage    94.46%   94.4%   -0.07%     
==========================================
  Files           78      78              
  Lines         4555    4501      -54     
  Branches       912     912              
==========================================
- Hits          4303    4249      -54     
  Misses         118     118              
  Partials       134     134

Impacted Files	Coverage Δ
samtranslator/plugins/exceptions.py	83.33% <0%> (-2.39%)	⬇️
samtranslator/model/iam.py	92.85% <0%> (-1.43%)	⬇️
samtranslator/translator/arn_generator.py	86.95% <0%> (-0.55%)	⬇️
samtranslator/model/sqs.py	93.33% <0%> (-0.42%)	⬇️
samtranslator/validator/validator.py	95.23% <0%> (-0.42%)	⬇️
samtranslator/open_api/open_api.py	93.6% <0%> (-0.29%)	⬇️
samtranslator/swagger/swagger.py	92.77% <0%> (-0.13%)	⬇️
samtranslator/model/__init__.py	98.11% <0%> (-0.04%)	⬇️
samtranslator/plugins/globals/globals.py	99.02% <0%> (-0.03%)	⬇️
samtranslator/model/sam_resources.py	93.97% <0%> (-0.02%)	⬇️
... and 8 more

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[praneetap]

Thanks for the contribution!

[keetonian]

All policies require resource (*): https://docs.aws.amazon.com/IAM/latest/UserGuide/list_amazontextract.html

Full access policy as shown here exists in AWS textract docs: https://docs.aws.amazon.com/textract/latest/dg/using-identity-based-policies.html#access-policy-customer-managed-second-example