Support Sensu Go 5.6

[treydock]

Pull Request Checklist

Description

• Fix issue when sensuctl list returns null
• Use shared code to handle parsing output from sensuctl list
• Support trusted_ca_file, client_cert_file and client_key_file for AD and LDAP auth
• Make server_binding optional for AD and LDAP auth

Related Issue

Works around issue sensu/sensu-go#2915

Motivation and Context

Sensu-Go 5.6 made AD and LDAP authentication optional. Also new properties for AD and LDAP were added to supply CA certs and keys. An issue was discovered where sensuctl <resource> list will return null instead of empty array and this PR addresses that and moves the JSON parsing logic to shared function.

How Has This Been Tested?

Unit and acceptance

[treydock]

Added commit that should fix failures with clusters. The JSON from --format json for cluster commands is actually two separate JSON structures so updated logic to handle old and new formats.

[ghoneycutt]

Released in v3.2.0