[roll pigweed] pw_software_update: Add pw_protobuf-based service

Previously, pw_software_update only had a nanopb RPC
BundledUpdateService. This commit adds a new version of the service that
uses pw_protobuf RPC.

The service was essentially copy-pasted from the nanopb version, with
changes made to the RPC method handlers to use all of the new types.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/104866

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: e16a89da070b72e..f62d19548d862e2
Roller-URL: https://ci.chromium.org/b/8806351002245252017
Cq-Cl-Tag: roller-builder:pigweed-zephyr-roller
Cq-Cl-Tag: roller-bid:8806351002245252017
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I51bacee5058d1ce3ec61d7810b84d773f1b9ece5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/105508
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