Building on top of the work done in commands to account for GH_REPO environment variable, this commit expands existing tests around handling base repo functions to include new test scenarios.
These tests fail in the same way as reported on the issue when run against `trunk` without the other branch's changes, demonstrating they will help avoid regression.
This change updates `gh variable delete` and `gh secret delete` to use the host associated with the repository rather than the default host. Along with these changes is minor refactoring of the tests to ensure appropriate Dotcom vs GHES targeting works as expected.
Minor edit to `gh variable get` testing to simplify some conditional logic in test setup.
