the idea is to create an equivalent to the kernel events like request, controller, view, response.

this would allow doing common dynamic setup tasks (like doing some dynamic configuration inside a storage API). but it maybe we also want to have additional events fired in other cases, like when an uncaught exception happens or to maintain an audit log of CLI command calls.

my personal example use case is wanting to set a dynamic HTTP header in all commands calling a backend through a load balancer that picks the server based on said HTTP header.

see also #1884 for why a tag and not an event listener