site enable command should first check if site can launch without errors
What currently happens
site enable command installs the site to be launched by systemd. However, currently, it succeeds if the installation succeeds even if the site does not launch correctly (e.g., due to a runtime exception in a dynamic route, etc.)
What should happen
The command should test that the site can launch properly before installing it and if not, it should fail and display the relevant error information.