Breadcrumb handling not implemented to spec on the server

[bzbarsky-apple]

Problem

The current state of breadcrumb handling on the server is:

1. We have a breadcrumb in the configuration manager. It's written by SetRegulatoryConfig and read by absolutely nothing.
2. We have a breadcrumb attribute in the attribute store. It's written by writes to that attribute and read by reads of that attribute.
3. None of the commands that carry a breadcrumb update the attribute state.

Proposed Solution

1. Have a single source of truth for breadcrumb. This should be the attribute store, because that causes the smallest number of complications.
2. Ensure attribute reads and writes use the source of truth. This is automatic if we use the attribute store.
3. Ensure all commands that take a breadcrumb field update the breadcrumb: call the relevant Set() method from Accessors.h, or add an API on the general commissioning cluster.
4. Remove the persistent configuration manager storage of breadcrumb.

This is critical to having sane error recovery during commissioning.

[bzbarsky-apple]

#17769 fixed most of this. The remainder is tracked in #17759