Rename classes with name 'MasterService' to 'ClusterManagerService' in directory 'test/framework'

[tlfeng]

Description

To support inclusive language, the master terminology is going to be replaced by cluster manager in the code base.

After the class MasterService has been deprecated and class ClusterManagerService has been created in #4022 / commit 740f75d, the classes in test/framework directory with name 'MasterService' can be deprecated and renamed.

• Rename the following classes in test/framework directory:

FakeThreadPoolMasterService -> FakeThreadPoolClusterManagerService
BlockMasterServiceOnMaster -> BlockClusterManagerServiceOnClusterManager
BusyMasterServiceDisruption -> BusyClusterManagerServiceDisruption

In the following PR (#4058), I will add back the above 3 classes with the old name and deprecate them, to keep the backwards compatibility.

Issues Resolved

A part of issue #3543

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.