Implement getIssueNumber and getPullNumber

[katieshin]

Description

Implement getIssueNumber and getPullNumber as requested in Issue 347. Tests are difficult to write because there are no existing tests that reach the methods in this particular class (GHThread).

Before submitting a PR:

• 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.
• Add JavaDocs and other comments as appropriate. Consider including links in comments to relevant documentation on https://docs.github.com/en/rest .
• 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.
• Push your changes to a branch other than main. You will create your PR from that branch.

When creating a PR:

• 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.
  • Provide links to relevant documentation on https://docs.github.com/en/rest where possible.
• All lines of new code should be covered by tests as reported by code coverage. Any lines that are not covered must have PR comments explaining why they cannot be covered. For example, "Reaching this particular exception is hard and is not a particular common scenario."
• Enable "Allow edits from maintainers".

[codecov]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Files	Coverage Δ
src/main/java/org/kohsuke/github/GHThread.java	27.27% <0.00%> (-3.77%)	⬇️

... and 203 files with indirect coverage changes

📢 Thoughts on this report? Let us know!.

[bitwiseman]

Tests are difficult to write because there are no existing tests that reach the methods in this particular class (GHThread).

There seem to be at least some tests that do touch this class:
https://app.codecov.io/gh/hub4j/github-api/blob/main/src/main/java/org/kohsuke/github/GHThread.java

I'm not sure which ones they are, but ... Could at least take a look for them. Adding methods without coverage is something we really want to avoid if at all possible.

[katieshin]

Got it, I'll keep working on the tests. Thanks!