Add GHOrganization.listSecurityManagers()

[kozmic]

Description

Add support to list Security Managers in a GitHub Organization. See GitHub's API doc for this API for more details about this API.

Tests:

If I'm given access to the hub4j-test-org Org, including permission to create a team and configure that team as a Security Manager team (or someone else can set this up for me), I can include an integration test (I didn't find a step-by-step process in CONTRIBUTING.md to get this access.

Before submitting a PR:

• [x] Changes must not break binary backwards compatibility. If you are unclear on how to make the change you think is needed while maintaining backward compatibility, CONTRIBUTING.md for details.
• [x] Add JavaDocs and other comments explaining the behavior.
• [ ] When adding or updating methods that fetch entities, add @link JavaDoc entries to the relevant documentation on https://docs.github.com/en/rest .
• [x] Add tests that cover any added or changed code. This generally requires capturing snapshot test data. See CONTRIBUTING.md for details.
• [ ] Run mvn -D enable-ci clean install site locally. If this command doesn't succeed, your change will not pass CI.
• [x] Push your changes to a branch other than main. You will create your PR from that branch.

When creating a PR:

• [x] Fill in the "Description" above with clear summary of the changes. This includes:
  • [ ] If this PR fixes one or more issues, include "Fixes #" lines for each issue.
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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 81.03%. Comparing base (c2ac4b0) to head (92112af). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1832 +/- ## ========================================= Coverage 81.03% 81.03% - Complexity 2409 2411 +2 ========================================= Files 233 233 Lines 7344 7347 +3 Branches 399 399 ========================================= + Hits 5951 5954 +3 Misses 1148 1148 Partials 245 245 ```

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[kozmic]

@bitwiseman : I would love to, but you need to add me to the test org so I can add a security maanger to run the tests against. Or is a unit test good enough for you?

From the description of this PR:

If I'm given access to the hub4j-test-org Org, including permission to create a team and configure that team as a Security Manager team (or someone else can set this up for me), I can include an integration test (I didn't find a step-by-step process in CONTRIBUTING.md to get this access.

[kozmic]

@bitwiseman : I've added test response files that I've manually created and created unit tests based on those. Let me know if you want me to have real files from your test org, then you need to add me with permission to add a security team to the test org (or you can do it, and give me read access).

[kozmic]

@bitwiseman : Could you take a look at this?