Add write roundtrip test

[bzbarsky-apple]

Problem

We don't have a unit test for a round-trip write: instantiate a WriteClient, do a write on it, have that create a WriteHandler on the destination, respond, etc.

Change overview

Adds such a test.

Testing

Ran the unit tests. This uncovered a few bugs in our implementation that are fixed as part of the PR.

Reviewer note

Reviewing the two changesets in this PR separately might be simpler than reviewing the overall diff.

[yunhanw-google]

thanks

[todo]

libAppTests depends on MessagingTestHelpers, which depends on

connectedhomeip/scripts/tests/esp32_qemu_tests.sh

Lines 64 to 74 in a9de05b

	# TODO: libAppTests depends on MessagingTestHelpers, which depends on
	# NetworkTestHelpers. That sort of depends on InetTestHelpers or
	# equivalent (to provide gSystemLayer, gInet, InitNetwork(),
	# ShutdownNetwork()) but there's only a POSIX implementation of that
	# last, which does not compile on ESP32. Need to figure out how to
	# make that work. See comments below for the transport layer tests,
	# which have the same issue.
	# run_suite libAppTests.a -lMessagingTestHelpers -lNetworkTestHelpers
	run_suite libASN1Tests.a
	run_suite libBleLayerTests.a

---

This comment was generated by todo based on a TODO comment in a9de05b in #8169. cc @bzbarsky-apple.

[github-actions]

Size increase report for "esp32-example-build" from 046f46a

File	Section	File	VM
chip-lock-app.elf	.flash.text	-64	-64

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-persistent-storage.elf and ./pull_artifact/chip-persistent-storage.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-pigweed-app.elf and ./pull_artifact/chip-pigweed-app.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-lock-app.elf and ./pull_artifact/chip-lock-app.elf:

sections,vmsize,filesize
[Unmapped],0,64
.debug_info,0,21
.debug_abbrev,0,12
.debug_line,0,10
.debug_str,0,2
.debug_ranges,0,-8
.flash.text,-64,-64
.debug_loc,0,-177

Comparing ./master_artifact/chip-temperature-measurement-app.elf and ./pull_artifact/chip-temperature-measurement-app.elf:

sections,vmsize,filesize
.debug_info,0,20
.debug_abbrev,0,12
.debug_line,0,10
.debug_str,0,2
.debug_ranges,0,-8
.debug_loc,0,-184

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.debug_info,0,20
.debug_abbrev,0,12
.debug_line,0,10
.debug_str,0,-2
.debug_ranges,0,-8
.debug_loc,0,-184

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize

[bzbarsky-apple]

@msandstedt @saurabhst Please take a look?