PortChannel - Fixes to check Ip address accepts array

[rahul-1475]

• Check if port channel accepts mutiple ip address.
• if accepts mutiple ip change db property to array to save multiple ip.

[rahul-1475]

pr link: https://github.com/STORDIS/orca_backend/pull/62

This issue also includes fixes for issue - https://github.com/STORDIS/orca_backend/issues/58

[rahul-1475]

• checked by adding multiple ip as array and found that server always replaces last elemnt of array.
• In cli one one ip address is allowed.
• added test case to check to delete ip without sending ip in body