[FLINK-16089][docs] Translate "Data Type" page of "Table API & SQL" into Chinese

[gauss1314]

What is the purpose of the change

This pull request translates "Data Type" page of "Table API & SQL" into Chinese.

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

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/Mesos, 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)

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[wuchong]

Hi @danny0405 , could you help to review this?

[danny0405]

@wuchong , sure, let me take the review work.

[wuchong]

LGTM. Thanks for the contribution @gauss1314 and thanks for the reviewing @danny0405 .

Will slightly modify it and merge it.

[wuchong]

Suggested change

	然而,`TypeInformation` 并不是被设计为表示独立于 JVM class 的逻辑类型。之前很难将 SQL 的标准类型映射到 `TypeInformation` 抽象。此外，有一些类型并不是兼容 SQL 的并且在没有更好的规划的时候被引进。
	然而,`TypeInformation` 并不是为独立于 JVM class 的逻辑类型而设计的。之前很难将 SQL 的标准类型映射到 `TypeInformation` 抽象。此外，有一些类型并不是兼容 SQL 的并且引入的时候没有长远规划过。

[wuchong]

Suggested change

	从 Flink 1.9 开始，Table & SQL API 将接收一种新的类型系统作为长期解决方案，用来保持 API 稳定性和 SQL 标准的兼容性。
	从 Flink 1.9 开始，Table & SQL API 开始启用一种新的类型系统作为长期解决方案，用来保持 API 稳定性和 SQL 标准的兼容性。

[wuchong]

Suggested change

	Flink 的数据类型和 SQL 标准的 *数据类型* 术语类似，但也包含了 nullability 信息，可以被用于 scala expression 的优化。
	Flink 的数据类型和 SQL 标准的 *数据类型* 术语类似，但也包含了可空属性，可以被用于标量表达式（scalar expression）的优化。