[improve][broker] Add methods for batch updating and deleting bookie rack information

[hrzzzz]

Motivation

We can add admin APIs for batch updating or deleting bookie rack info to reduce write operations to ZooKeeper.

Modifications

Add admin APIs:

• batchDeleteBookiesRackInfo
• batchUpdateBookiesRackInfo

Verifying this change

• [ ] Make sure that the change passes the CI checks.

Added tests:

• org.apache.pulsar.broker.admin.BookiesApiTest#testUpdateBookieRackInfo
• org.apache.pulsar.broker.admin.BookiesApiTest#testDeleteBookieRackInfo
• org.apache.pulsar.broker.admin.BookiesApiTest#testClearAllBookiesRackInfo

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
• [x] The REST endpoints
• [x] The admin CLI options
• [ ] The metrics
• [ ] Anything that affects deployment

Documentation

• [ ] doc
• [ ] doc-required
• [x] doc-not-needed
• [ ] doc-complete

Matching PR in forked repository

PR in forked repository: https://github.com/hrzzzz/pulsar/pull/6