Add solution design for Authn-K8s namespace label constraint

[john-odonnell]

Desired Outcome

Add solution design for Authn-K8s namespace label constraint

Implemented Changes

N/A

Connected Issue/Story

CyberArk internal issue link: ONYX-21265

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be merged.

Changelog

• [ ] The CHANGELOG has been updated, or
• [x] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [x] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: insert issue ID
• [x] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [x] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [ ] There are no security aspects to these changes

[codeclimate[bot]]

Code Climate has analyzed commit b0f89782 and detected 80 issues on this pull request.

Here's the issue category breakdown:

Category	Count
Style	80

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 90.0% (-1.5% change).

View more on Code Climate.