Add Cisco ZTPv6 Support

[hrvach]

Adding ZTPv6 Cisco support based on Option 17 Suboption 1 (Vendor Specific Information Option).

[pmazzini]

Thanks for the PR, please sign the commit. Here there is info on how to do it: https://github.com/insomniacslk/dhcp/pull/472/checks?check_run_id=7898850600

[codecov[bot]]

Codecov Report

Merging #472 (ec5c7ba) into master (509691f) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #472   +/-   ##
=======================================
  Coverage   67.45%   67.45%           
=======================================
  Files          90       90           
  Lines        3767     3767           
=======================================
  Hits         2541     2541           
  Misses       1054     1054           
  Partials      172      172           

Flag	Coverage Δ
integtests	∅ <ø> (∅)
unittests	67.45% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
dhcpv6/ztpv6/parse_vendor_options.go	89.74% <100.00%> (ø)

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[hrvach]

Thanks for the PR, please sign the commit. Here there is info on how to do it: https://github.com/insomniacslk/dhcp/pull/472/checks?check_run_id=7898850600

Thanks Pablo, signed!