[FLINK-13239][ml] Add unary loss functions

[xuyang1706]

What is the purpose of the change

Add unary loss function's interface and 9 common used functions:

1. ExponentialLossFunc
2. HingeLossFunc
3. LogisticLossFunc
4. LogLossFunc
5. PerceptronLossFunc
6. ZeroOneLossFunc
7. SquareLossFunc
8. SvrLossFunc
9. HuberLossFunc

More information about loss function, please see：

• https://en.wikipedia.org/wiki/Loss_function
• https://en.wikipedia.org/wiki/Loss_functions_for_classification

Brief change log

• add the interface of unary loss function
• add 9 common used functions
• add unit tests

Verifying this change

This change added tests and can be verified as follows:

• run test case pass

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

• Dependencies (does it add or upgrade a dependency): (yes)
• 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, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (yes)
• If yes, how is the feature documented? (JavaDocs)

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CI report:

• 1779173 : SUCCESS Build