feat(parsers.avro): Allow connection to https schema registry

[BelousovAntonV]

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• Updated associated README.md.
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Resolves #13334

Authorization base64 string and ca certificate path options are added to the config. Now creating a client instead of simple request to the schema registry.

[telegraf-tiger]

Thanks so much for the pull request!
🤝 ✒️ Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[BelousovAntonV]

!signed-cla

[srebhan]

Thank you for the valuable contribution @BelousovAntonV! I have some comments with the most important one being to split the authentication option into username and password to ease the use.

Alternatively, we can pass in credentials via the avro_schema_registry option e.g.
avro_schema_registry = "http://evil:bifh@localhost:8081". What do you think?

[srebhan]

@BelousovAntonV I incorporated my suggestions in #13903 and am closing this PR in favorite of the other one...

[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 -1.02 % for linux amd64 (new size: 195.0 MB, nightly size 197.0 MB)

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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_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

[BelousovAntonV]

@BelousovAntonV I incorporated my suggestions in #13903 and am closing this PR in favorite of the other one...

Thank you a lot. Did not have a chance to work on it.