test(outputs.azure_monitor): Cleanup tests and add a unit-test for time-limit handling

[srebhan]

Summary

This cleans up the unit-tests to not distribute the code for defining the plugin under test. Furthermore, the PR adds two unit-tests for mocking the upstream time limitations.

Checklist

• No AI generated code was used in this PR

Related issues

[telegraf-tiger]

Download PR build artifacts for linux_amd64.tar.gz, darwin_arm64.tar.gz, and windows_amd64.zip.
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DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz
		linux_s390x.tar.gz