Add connect/close/endpoint method to ZmqClient/ZmqServer.

[liuh-80]

Why I did it

GO will manage resource by GC, ZmqClient/ZmqServer contains system resource need release explicitly.

How I did it

Add connect/close/endpoint method to ZmqClient/ZmqServer.

Work item tracking

• Microsoft ADO: 27350797

How to verify it

Pass all test cases.

Which release branch to backport (provide reason below if selected)

• [ ] 201811
• [ ] 201911
• [ ] 202006
• [ ] 202012
• [ ] 202106
• [ ] 202111

Description for the changelog

Add connect/close/endpoint method to ZmqClient/ZmqServer.

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)