[refactor][cli][PIP-280] Refactor CmdNamespace for parameters with measurement units

[JooHyukKim]

PIP: #20691

Motivation

Described in PIP

Modifications

Described in PIP

Verifying this change

• Make sure that the change passes the CI checks.

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: https://github.com/JooHyukKim/pulsar/pull/15

[JooHyukKim]

Will close this one becasue all of following classes have very smiliar changes and so I will try to refactor them all at once.

• CmdNamespaces.java
• CmdTopics.java,
• CmdTopicPolicies.java.