docs(data-classes): make authorizer concise; use enum

[heitorlessa]

Issue #, if available: #620

Description of changes:

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

Breaking change checklist

RFC issue #:

• Migration process documented
• Implement warnings (if it can live side by side)

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

---

View rendered docs/utilities/data_classes.md

[codecov-commenter]

Codecov Report

Merging #630 (48455fd) into develop (d02dd2e) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop     #630   +/-   ##
========================================
  Coverage    99.95%   99.95%           
========================================
  Files          115      115           
  Lines         4828     4832    +4     
  Branches       265      266    +1     
========================================
+ Hits          4826     4830    +4     
  Partials         2        2           

Impacted Files	Coverage Δ
...ities/data_classes/api_gateway_authorizer_event.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d02dd2e...48455fd. Read the comment docs.