CustomProcedure (annotations 2.5.0 API)

```
@Target(METHOD)
@Retention(RUNTIME)
public @interface CustomProcedure
```
This annotation can be used to annotate a procedure in the same way as using `@Procedure` would. However, this annotation does not actually register anything with the procedure framework. We can use it to provide as quasi-equivalent method for out documentation and test tooling for procedures and functions that cannot use actual procedure framework annotations. It can also be used to pretend that `@UserAggregationFunction`s have a `@Procedure` annotation.
The return type of the annotated method should be a proper Java interface, not a Map, so that we can extract the schema from the fields. Only fields marked with the nested `@CustomProcedure.ResultField` annotation are included in the schema.
The parameters of the annotated method should be annotated with `@Name` as you would for regular `@Procedure` methods.

- Required Element Summary
  
  Required Elements
  Modifier and Type Required Element Description
  
  java.lang.String value
  The name of the procedure.
- Optional Element Summary
  
  Optional Elements
  Modifier and Type Optional Element Description
  
  CustomProcedure.Namespace namespace
  The namespace of the procedure.

- Element Detail
  - value
```
java.lang.String value
```
    The name of the procedure.
- - namespace
```
CustomProcedure.Namespace namespace
```
    The namespace of the procedure.
    
    Default:
    
    org.neo4j.gds.annotation.CustomProcedure.Namespace.PROCEDURE