KEP-4222: CBOR Serializer (#4223)

* KEP-4222: CBOR Serializer

* add test requirements for interoperability with implementations in other languages

* elaborate on client write negotiation and gating

* update kep number and status in kep.yaml

* clarify encode behavior for non-utf-8 strings

* complete scalability section of prr questionnaire

* require tests for client gating and fallback

* elaborate on unbuffered watch streaming

* add optional interface for encode

* outstanding scalability prr responses

* revise section on client-side feature gates

* support for apply configs

* add smp

* settle behavior for unrecognized field on decode

* bypass request content-type fallback with openapi

* consider cost of introduced randomness

* add kep-4222 prr file

* explain how to reencode stored cbor-encoded crs on rollback

* add test cases covering RawExtension

* require review and decision on nondeterministic encoding for beta

* fix typo

* update approvers and prr alpha approver

keps/prod-readiness/sig-api-machinery/4222.yaml

@@ -0,0 +1,3 @@
+kep-number: 4222
+alpha:
+  approver: "@deads2k"