Coding Agent: Handle opening multiple session logs for same PR

[bamurtaugh]

Using latest VS Code Insiders, GHPRI pre-release, and Copilot Chat pre-release on Windows.

Steps to Reproduce:

1. Open https://github.com/microsoft/vscode-pull-request-github in VS Code Insiders
2. Open the PR overview page for a PR Copilot created for me (I'm using Add Cancel Review button to review submission interface #7317)
3. This PR has multiple sessions (the initial session, and then a follow-up session once I tagged @copilot in a comment for a change`):
4. ❔ I have trouble clicking View session if one log tab is already open. It seems the second session is opened and replaces the content in the original tab, but it isn't brought into focus