Add topic command unload

[zymap]

Motivation

• Add command unload

USED FOR:
    This command is used for unloading a topic.

REQUIRED PERMISSION:
    This command requires super-user permissions.

EXAMPLES:
    #Unload a topic <topic-name>
    pulsarctl topic unload <topic-name>

OUTPUT:
    #normal output
    Unload topic <topic-name> successfully

    #the topic name is not specified
    [✖]  only one argument is allowed to be used as a name

    #the specified topic does not found
    [✖]  code: 404 reason: Topic not found

    #the topic name is not in the format of <tenant>/<namespace>/<topic> or <topic>
    [✖]  Invalid short topic name '<topic-name>', it should be in the format of <tenant>/<namespace>/<topic> or <topic>

    #the topic name is not in the format of <domain>://<tenant>/<namespace>/<topic>
    [✖]  Invalid complete topic name '<topic-name>', it should be in the format of <domain>://<tenant>/<namespace>/<topic>

    #the topic name is not in the format of <tenant>/<namespace>/<topic>
    [✖]  Invalid topic name '<topic-name>', it should be in the format of<tenant>/<namespace>/<topic>

    #the namespace name is not in the format of <tenant>/<namespace>
    [✖]  The complete name of namespace is invalid. complete name : <namespace-complete-name>

    #the tenant name and(or) namespace name is empty
    [✖]  Invalid tenant or namespace. [<tenant>/<namespace>]

    #the tenant name contains unsupported special chars. the alphanumeric (a-zA-Z0-9) and the special chars (-=:.%)  is allowed
    [✖]  Tenant name include unsupported special chars. tenant : [<namespace>]

    #the namespace name contains unsupported special chars. the  alphanumeric (a-zA-Z0-9) and the special chars (-=:.%) is allowed
    [✖]  Namespace name include unsupported special chars. namespace : [<namespace>]

Usage: pulsarctl topics unload [flags]

[zymap]

@sijie PTAL. Thanks.

[zymap]

@sijie PTAL. Thanks.