gh codespace commands now respect the following environment variables:
- GITHUB_SERVER_URL: typically "https://github.com"
- GITHUB_API_URL: typically "https://api.github.com"
- INTERNAL_VSCS_TARGET_URL: typically "https://online.visualstudio.com"
- GITHUB_TOKEN when CODESPACES is set, even if the host connecting to isn't "github.com".
This set of changes ensures that `gh codespace` commands automatically connect to the right API endpoints when gh is used within a codespace.
Co-authored-by: Mislav Marohnić <mislav@github.com>
