Implement Protocol Upgrade Logic for ChunkBody Data Model Upgrade

[jordanschalm]

Context

#6744 implements a backward-compatible data model change to ChunkBody. Because the old data model does not support service events outside the system chunk, before emitting such a service event, we need to coordinate a Protocol Upgrade after which the old data model is no longer supported.

A detailed plan outlining the steps and software behaviours for this is EFM Recovery Release/Upgrade Plan (Notion).

Definition Of Done

Implement the plan (TODO: fill this in once team agrees on plan as outlined).