tree cf2978f0fe6e97c6e13efa63425bbf27a353ca88
parent b63aa6ec46fec565d3f5f5b477700625f5357ed4
author Alexei Frolov <frolv@google.com> 1589228447 -0700
committer Alexei Frolov <frolv@google.com> 1589391653 -0700

pw_protobuf: Reimplement decoder as field iterator

This changes the pw::protobuf::Decoder API to expose functions to
iterate over fields instead of using a virtual callback interface,
making the core decoder simpler and more flexible.

The virtual callback interface is kept but renamed to a CallbackDecoder,
and reimplemented in terms of basic Decoder.

Change-Id: Idff321cd5e37184aa730251475c9e336136596d2