Add the math module to the Starlark Processor

[essobedo]

Required for all PRs:

• Updated associated README.md.
• Wrote appropriate unit tests.

resolves #8985

Motivation

The math module has been added recently to the upstream project starlark-go, we would like to make the Starlark processor support it too

Modifications:

• Adds the math module in the list of external modules to load
• Adds a simple example showing how to use it
• Update the README.md to refer the new example

Result

We can use math functions in the Starlark scripts executed by the Starlark Processor.

[telegraf-tiger]

🤝 ✅ CLA has been signed. Thank you!

[telegraf-tiger]

Looks like new artifacts were built from this PR. Get them here!

Artifact URLs

• aarch64.rpm

• armel.rpm

• armv6hl.rpm

• i386.rpm

• ppc64le.rpm

• s390x.rpm

• x86_64.rpm

• darwin_amd64.tar.gz

• freebsd_amd64.tar.gz

• freebsd_i386.tar.gz

• linux_amd64.tar.gz

• linux_arm64.tar.gz

• linux_armel.tar.gz

• linux_armhf.tar.gz

• linux_i386.tar.gz

• linux_mips.tar.gz

• linux_mipsel.tar.gz

• linux_ppc64le.tar.gz

• linux_s390x.tar.gz

• static_linux_amd64.tar.gz

• windows_amd64.zip

• windows_i386.zip

• amd64.deb

• arm64.deb

• armel.deb

• armhf.deb

• i386.deb

• mips.deb

• mipsel.deb

• ppc64el.deb

• s390x.deb

[ssoroka]

do we need to update Starlark versions for this? I guess not if it passes. :D

[essobedo]

do we need to update Starlark versions for this? I guess not if it passes. :D

Yes indeed we don't need as it has already been updated within the context of #9004