[improve][txn] Add admin api getOwnedTransactions

[hrzzzz]

Motivation

Add an admin API to query the metadata of transactions created by a specific user.

Modifications

Add an admin API to query the metadata of transactions created by a specific user.

Verifying this change

• Make sure that the change passes the CI checks.

This change added tests and can be verified as follows:

• Added test in: org.apache.pulsar.broker.admin.v3.AdminApiTransactionTest#testGetOwnedTransactions

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: hrzzzz#9