added certz4.1 (openconfig#3350)

* added certz4.1

* fixed the readme under tests

* fixed the metadata.textproto file

* fixed the deprecated functions of DialOption

* modified trustbundle_test

* fixed the static error

* certz4 f:ten care of the feedback comments

* fixed the path of files

* fixed with the latest feedback comments

* Update README.md

* fixed the README path

* fixed the fmt error

* fixed metadata file

* modified cleanup

* added go mod files

* modified as per certz4.1 given feedback

* fixed end of line error in the static check

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Co-authored-by: lvaish05 <168406079+lvaish05@users.noreply.github.com>
Co-authored-by: Chris Morrow <chris+github@as701.net>

Author: 3 people