ArgumentHint (Flink : Table : Common 2.0-preview1 API)

```
@PublicEvolving
@Retention(RUNTIME)
@Target({TYPE,METHOD,FIELD,PARAMETER})
public @interface ArgumentHint
```
A hint that provides additional information about an argument.
An ArgumentHint can be used to provide hints about the name, optionality, and data type of argument.
It combines the functionality of FunctionHint.argumentNames() and DataTypeHint annotations to conveniently group argument-related information together in function declarations.
@ArgumentHint(name = "in1", type = @DataTypeHint("STRING"), isOptional = false is an argument with the type String, named in1, and cannot be omitted when calling.

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`boolean`	`isOptional`	Specifies whether the argument is optional or required.
`String`	`name`	The name of the argument.
`DataTypeHint`	`type`	The data type hint for the argument.

- Element Detail
  - name
```
String name
```
    The name of the argument.
    This can be used to provide a descriptive name for the argument.
    
    Default:
    
    ""
- - isOptional
```
boolean isOptional
```
    Specifies whether the argument is optional or required.
    If set to true, the argument is considered optional.And if the user does not specify this parameter when calling, 'null' will be passed in. By default, an argument is considered required.
    
    Default:
    
    false
- - type
```
DataTypeHint type
```
    The data type hint for the argument.
    This can be used to provide additional information about the expected data type of the argument. The DataTypeHint annotation can be used to specify the data type explicitly or provide hints for the reflection-based extraction of the data type.
    
    Default:
    
    @org.apache.flink.table.annotation.DataTypeHint