fix(inputs.opcua): Auto fan out array nodes into individual fields

[inhinias]

Summary

Reading an entire OPC-UA array results in the metric creation to fail silently and reading an individual array element result in a bad node ID.

This PR detects an array and fans it out. So a read array results in each index being collected as a separate metric e.g: MetricName + Index.

This is just a simple way to get it to work. Maybe there is a way to store entire array as a metric, but I'm not all too familiar with the codebase as a whole. Options welcome.

Also Note:

• Reading an array structure e.g: NodeId.Foo[1].bar works
• Reading a single index does not work as mentioned above. (This PR does not fix this) For that OpcUa indexRange must be used together with some parsing of the node id so classical [index] notation can be used. See: https://reference.opcfoundation.org/Core/Part4/v104/docs/7.24

Checklist

• No AI generated code was used in this PR

Related issues

resolves #11898

[telegraf-tiger]

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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_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
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