Add Support For Showing a Custom Type View via TypeCustomDebugDataView or Annotations

Hi,

It seems currently vscode-java-debug doesn't support a way to have different representations of a type during debug in inline view, "variables" and "watch" windows.

Environment

• Operating System: Windows 10 19043.1645 (x64)
• JDK version: Java 11 (Oracle JDK 16)
• Visual Studio Code version: 1.66.2
• Java extension version: 1.6.0
• Java Debugger extension version: 0.40.1

Steps To Reproduce

1. Start a debugging session in vscode for any java file.
2. See how class variables are represented in inline-view, "variables" and "watch" windows.

Current Result

For example, here is how it looks like during debug - inline view (extension version v0.40.1):

and here is overridden toString method in the Point class:

notice, I have the following options in .vscode/settings.json:

{
  "java.debug.settings.showQualifiedNames": false,
  "java.debug.settings.showToString": true,
  "java.debug.settings.showLogicalStructure": true
}

also, when I expand an array in the variable view, the nested types are not showing until I click(...):

It seems there are no ways to enable a custom data view for a particular types, right?

Expected Result

It would be cool to have something like that:

It seems like it can be done using either:

1. Adding an option to enable displaying a result of overridden toString method, e.g. java.debug.settings.showToStringInlineView: true
2. Add "Java Type Renderer" to support custom data views similar to IntellijIdea "debugger -> Customize Data Views -> Java Type Renderer" (see link #1 in Additional Informations)
3. Add something like DebuggerDisplay annotation similar to C# DebuggerDisplayAttribute (see link #2 in Additional Informatins)

For me the second way seems more appealing because it may allow setting custom debug views even for Java internal classes like java.utils.ArrayList

Additional Informations

For example, here are some StackOverflow questions that illustrate the problem:

1. IntelliJ change toString for debug mode (variables view) | StackOverflow
2. Display custom string in debugger variables | StackOverflow

Non sono nominati file sorgente, test o punti di ingresso. Inizia tracciando il modo in cui vscode-java-debug esegue il rendering dei valori nelle viste inline, Variables e Watch, quindi confronta gli approcci proposti TypeCustomDebugDataView, annotation e toString. Il lavoro sarà considerato completato quando sarà stato concordato un design e saranno supportate rappresentazioni personalizzate dei tipi nelle viste richieste.