Resolve "Implement missing functionality of subscription management"

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Related to #385

cli/cmd/subManagement.go

@@ -43,6 +43,8 @@ var subCmd = &cobra.Command{
 	Long:    `The subscription command contains all sub-commands for subscription management. It has no functionality in itself.`,
 }
 
+var subUUID string
+
 func init() {
 	rootCmd.AddCommand(subCmd)
 }