[roll third_party/pigweed] pw_rpc: Expand callback tests

- Rework existing test to extract reusable components.
- Add tests for moving calls in the callback and from another thread.
- Disable failing tests. These will be enabled in a subsequent CL.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/126770

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 7b8111f2bb716dd..22e8afc8ec6e3a6
Roller-URL: https://ci.chromium.org/b/8791140184000882113
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I38ff4339d8311c3f48a12704045e3e9eba698a66
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/126817
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 7b8111f..22e8afc 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 7b8111f2bb716dd2383e3553dcaea115e7f8dd04
+Subproject commit 22e8afc8ec6e3a605d32d8f7b58eba0a18d66c3c