[Fix][Connector-V2][Hbase] Fix source reader only scanning first split

[yzeng1618]

Fixes #10286

Purpose of this pull request

Fix a correctness issue in connector-hbase source: when multiple splits (regions) are assigned, HbaseSourceReader could effectively scan only the first split because an exhausted ResultScanner was reused for subsequent splits.
This PR creates a new ResultScanner per split, closes it after scanning, and adds a unit test to prevent regression.
A @VisibleForTesting constructor is added only to allow injecting a mocked HbaseClient in tests; the production behavior is unchanged.

Does this PR introduce any user-facing change?

Yes. For HBase source, the read count can now correctly include all assigned splits/regions. Previously, the job could finish successfully but read only a fraction of rows.

How was this patch tested?

Added unit test: HbaseSourceReaderTest

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If necessary, please update incompatible-changes.md to describe the incompatibility caused by this PR.
• If you are contributing the connector code, please check that the following files are updated:
  1. Update plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config

[yzeng1618]

After-repair Test Results

[chl-wxp]

LGTM

[corgy-w]

+1