roll: pigweed, pw_toolchain: pw_rpc: Fix open in callback_client

Inbound packets from open RPCs were mapped correctly to client calls,
but client-opened calls were not appropriately handled. Have client-
opened RPCs use the open call ID, and update open calls to use the call
ID of the first packet received for that RPC.

Original-Bug: b/309159260
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/169174
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 35c221facea3abd..2e5bb7f84aa7885
Roller-URL: https://ci.chromium.org/b/8739502805494361729
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I7dfd4881c10bc22add6cea1d54d4ebf74fde780c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/showcase/sense/+/229977
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>