Fixes T9719. Currently, the Herald "Test Console" has a big instanceof thing, so new adapters (like a Calendar adapter, or third-party adapters) aren't available automatically. Instead, do a standard modular thing: load the available adapters, ask which ones can test the object the user selected, then let the user pick which one they want to move forward with.
Additionally, it isn't very clear that you can't test "commit hook" rules because they rely on push state which we don't really have a good way to simulate. When the user picks a commit, we now show them the "Hook" events, but the options are disabled and explain why they can not be selected.