CleanKnob alarm (and certain other alarms) should be changed to warnings

[mmastrac]

Right now the code is intentionally ignoring some alarms that are non-fatal (currently just CleanKnob, but we'd probably want to add descaling):

https://github.com/mmastrac/longshot/blob/995bf7309336e24e060565527058c0445dec2349/src/ecam/ecam_wrapper.rs#L88

We should likely include certain alarms as a warning bitset for the ready state to alert the user that they may wish to take action on something before or after brewing.