Make Test Runner API/ Coverage API and Gototest API public APIs

### Description

quoted from a Netbeans dev :

> friend APIs are APIs which are not stable and therefore not public. If you want to use them anyway, you have to pretend to be a friend and use them. Since they can change from release to release, you have to do provide a build for every release

This do not make it easy for plugin developpers. It is the case with following APIs

https://github.com/apache/netbeans/tree/master/ide/gototest
https://github.com/apache/netbeans/tree/master/ide/gsf.codecoverage
https://github.com/apache/netbeans/tree/master/ide/gsf.testrunner

**DEV mail thread**: https://lists.apache.org/thread/rdwh4vh07zxgbxyjfzfhxd8yjk7o23wv

### Use case/motivation

As those 3 APIs are very important part of a Language support module they need to be made available to allow plugin developers to work with them more smoothly.

It is now several years since those APIs are not public if i am not wrong.

I worked with them recently and didn't noticed any instability or harm to the IDE.

### Related issues

_No response_

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

Yes

Start by reviewing the public API boundaries in ide/gototest, ide/gsf.codecoverage, and ide/gsf.testrunner, along with the linked NetBeans development discussion. Determine which friend APIs must be exposed and what stability or compatibility requirements apply; done means plugin developers can use all three APIs as supported public APIs.

Written by the indexing model from the issue text.