Add documentation and testing

[ewhanson]

The following need to be added for the public commenting feature

• API documentation
• Automated tests
• User-facing documentation on how to use comments as a commenter and moderator

Pull Requests

• Automated Tests

  ojs: pkp/pkp-lib#11732 Add tests for public comments ojs#5087
  pkp-lib: pkp/pkp-lib#11732 Add tests for public comments #11810

• API Documentation

  ojs: pkp/pkp-lib#11824 Add API documentation for public user comments ojs#5093

[taslangraham]

The tests are currently passing, but they might break once the changes from @jardakotesovec are merged. I’ll revisit and update them as needed after those changes go through.