Include Return Type Annotations in Method Hover Tooltip

Description
When hovering over a method in the editor, the tooltip currently shows the method signature and Javadoc (if available). However, annotations applied to the method’s return type are not displayed.

This feature request proposes enhancing the hover tooltip to include annotations declared on the return type.

Example

public @Nullable String getName() {
    return name;
}

or with type-use annotations:

public List<@NonNull String> getNames() {
    return names;
}

Current Behavior:
Hover tooltip shows:

String getName()

Expected Behavior:
Hover tooltip shows:

@Nullable String getName()

and for generics:

List<@NonNull String> getNames()

Motivation / Use Case
Return type annotations (e.g., nullability annotations like @Nullable, @NonNull, or custom type-use annotations) are critical for understanding API contracts, static analysis, and preventing runtime errors.

Not displaying them in hover:

• Hides important semantic information
• Forces developers to navigate to the declaration
• Reduces the usefulness of hover as a quick inspection tool

首先定位 VS Code 扩展中的 Java hover-tooltip 实现，并跟踪方法签名的渲染方式。使用 @Nullable 和 List<@NonNull String> 示例作为预期情况；当声明返回注解和类型使用返回注解都出现在 hover 输出中，并且相应的测试已添加或更新时，即表示完成。