Have server enforce SSH zone separation

[jjohnson42]

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When a client requests a zone's ssh credentials, make sure the client is consistent with the specified zone.

Per github user salben21

The PR is to fix issue 7246

The modification include

##item1

##item2

The UT result

##The UT output##

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Please remove this line and above for tasks or features

The PR is for task #xxx or to implement feature #xxx

##Feature description##

The content of the PR:

• [ ] ##The mini-design link
• [ ] ##The basic code logic

The UT result

##The UT output##