chore: Remove pipelines (#9509)

I started off just intending to remove the user-facing bits, but I figured I'd just remove it all while I was in here since it seemed unlikely that the re-implementation of pipelines would even be able to re-use any of this. I did leave in the concept of a ComponentKey though, to decouple from the component id, since I think this concept is likely to stick around. I did remove scope as a metric label though given the only scope right now is global.

Signed-off-by: Jesse Szwedko <jesse@szwedko.me>
Signed-off-by: Lee Benson <lee@leebenson.com>
Co-authored-by: Lee Benson <lee@leebenson.com>
Signed-off-by: Jesse Szwedko <jesse@szwedko.me>