Test issue and PR URL handling

[alexr00]

Refs: #6869

• macOS @osortega
• linux @DonJayamanne
• windows @lszomoru

Complexity: 2

Create Issue

---

Setup

• Install the pre-release version of GitHub Pull Requests
• Have a clone of a GitHub repo where you don't mind making a PR.

Testing

GitHub Pull Requests now knows how to open issue and PR links in the issue and PR webview. There are several places this works from:

• Linked items in the issue/PR timeline
• The issue/PR body, when the link is to an issue/pr in the same repo as the current issue/pr
  To test:
• Open an issue or PR item (click on it in the Issues or Pull Requests view) which has a linked item. Verify that if you click on the issue/PR linked in the linked item that it opens in a webview in VS Code
• Open an issue or PR item which has another issue or PR linked in the body. Verify that if you click on that link that it opens in a webview in VS Code.