[FEATURE] Clarify walkback logic for components

[cujomalainey]

Currently on failure many functions (e.g. volume prepare) exit and update their state but do not call the respective handler to properly transition to that state. Others clear local state but don't update their component state (smart amp prepare). Some just return an error (kpb prepare).

We need to standardize the error logic expectations from the for components. Will the pipeline call the respective exit handler automatically on error or will the component be expected to handle this itself? Should we even call the handler on error? How will this work in cases such as mixers? This will make reviewing expectations easier and prevent possible mismatches of behaviours on exit in the field.

[lgirdwood]

Pipeline 2.0 update will align new flow and supporting docs on sof-docs.