feat(inputs.opcua): add use regular reads workaround

[R290]

Required for all PRs

• Updated associated README.md.
• Wrote appropriate unit tests.
• Pull request title or commits are in conventional commit format

resolves #11559

Added workaround to use regular reads instead of registered reads.

[Hipska]

Have also a look at the test-go-linux check and fix the issues that come from it.
You can also run this on your local machine before pushing, see Unit Tests section.

[R290]

Good point on the make docs. I accepted your changes from within GitHub, so I didn't run any checks before committing. For some reason make check wants me to change 375 files (including opcua.go) using make fmt...

[telegraf-tiger]

Download PR build artifacts for linux_amd64.tar.gz, darwin_amd64.tar.gz, and windows_amd64.zip.
Downloads for additional architectures and packages are available below.

🥳 This pull request decreases the Telegraf binary size by -2.72 % for linux amd64 (new size: 148.5 MB, nightly size 152.6 MB)

📦 Click here to get additional PR build artifacts

Artifact URLs

DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_i386.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz
		static_linux_amd64.tar.gz

[powersj]

@R290 is this one ready to review or was there additional development required? Thanks!

[R290]

The attached issue contains of 2 parts, and this pull only resolves the second part:
telegraf needs to handle auto-reconnect and that we should reconsider using registered reads
For the first part some issues within the underlying opcua library need to be fixed, but this has been eerily quiet for the past six weeks or so. Feel free to review and merge though, the changes are only a small workaround.

[powersj]

Thanks for putting this up. fwiw I think I held off earlier because this was marked draft.

[LarsStegman]

I know this has already been merged, but it has not yet been released. Might I suggest using use_unregistered_reads as the config name. I think regular could be confusing.

[MyaLongmire]

@LarsStegman that's a great idea! Are you willing to put up a pr or should i?

[LarsStegman]

You can do it if you want 🙂

[MyaLongmire]

@LarsStegman pr can be found here :)