[FLINK-30194][runtime][security] Rename DelegationTokenProvider to HadoopDelegationTokenProvider

[gaborgsomogyi]

What is the purpose of the change

Rename DelegationTokenProvider to HadoopDelegationTokenProvider.
Please have a look at FLIP-272 for further details.

Brief change log

Rename DelegationTokenProvider to HadoopDelegationTokenProvider.

Verifying this change

Existing tests.

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

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

[gaborgsomogyi]

cc @mbalassi

[flinkbot]

CI report:

• e056ff0 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[mbalassi]

LGTM, will merge after the CI passes.

[mbalassi]

Please rebase @gaborgsomogyi

[gaborgsomogyi]

@mbalassi success w/ rebase.