fix(security): Mark AddRoute(unauthenticated) as Deprecated

[bnevis-i]

Closes #1437

Additionally adds error checks to unit tests

If your build fails due to your commit message not passing the build checks, please review the guidelines here: https://github.com/edgexfoundry/app-functions-sdk-go/blob/main/.github/CONTRIBUTING.md

PR Checklist

Please check if your PR fulfills the following requirements:

• [X] I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• [ ] I am not introducing a new dependency (add notes below if you are)
• [X] I have added unit tests for the new feature or bug fix (if not, why?)
• [X] I have fully tested (add details below) this the new feature or bug fix (if not, why?)
• [X] I have opened a PR for the related docs change (if not, why?) <link to docs PR>

Testing Instructions

"make test"

New Dependency Instructions (If applicable)

[codecov-commenter]

Codecov Report

Merging #1445 (2327eac) into main (10a2ee8) will not change coverage. The diff coverage is n/a.

:exclamation: Your organization is not using the GitHub App Integration. As a result you may experience degraded service beginning May 15th. Please install the Github App Integration for your organization. Read more.

@@           Coverage Diff           @@
##             main    #1445   +/-   ##
=======================================
  Coverage   66.83%   66.83%           
=======================================
  Files          36       36           
  Lines        3088     3088           
=======================================
  Hits         2064     2064           
  Misses        891      891           
  Partials      133      133