Rendered javadoc in code

### Description

It would be nice to have rendered javadoc comments in code. This can increase the readability of code. The same functionality has IDEA and it helps a lot see it in their documentation https://www.jetbrains.com/help/idea/javadocs.html#toggle-rendered-view .

### Use case/motivation

When a method, class etc. has a javadoc comment then this comment is rendered in code as you can see in the Javadoc window instead of raw javadoc.
E.g.:
```java
/**
* Represents an operation that accepts a single input argument and returns no
* result. Unlike most other functional interfaces, {@code Consumer} is expected
* to operate via side-effects.
*
*

This is a functional interface
* whose functional method is {@link #accept(Object)}.
*
* @param the type of the input to the operation
*
* @since 1.8
*/
```
there will be rendered javadoc:
"""
Represents an operation that accepts a single input argument and returns no result. Unlike most other functional interfaces, Consumer is expected to operate via side-effects.

This is a [functional interface](https://github.com/apache/netbeans/issues/package-summary.html) whose functional method is [accept(Object)](https://github.com/apache/netbeans/issues/*2).

Type Parameters:
   T - the type of the input to the operation
Since:
   1.8
"""

And it will be changed back to raw javadoc if the user click into this rendered part.

Current raw javadoc:
vs
Rendered javadoc example:

It will also help in the future when Javadoc supports Markdown [JEP 467: Markdown Documentation Comments](https://openjdk.org/jeps/467) and then different javadoc comment styles will be rendered the same.

### Related issues

_No response_

### Are you willing to submit a pull request?

No

The issue does not name implementation files or tests. Start by locating the Java editor's Javadoc rendering entry points and compare the requested toggle behavior with the linked IntelliJ documentation. Done means rendered Javadoc can be viewed in code and switched back to raw comments, with behavior covering the examples described.

Written by the indexing model from the issue text.