Support interactive formatter settings wizard

Currently we use Java: Open Java Formatter Settings to open the formatter settings profile (xml file), once the profile exists, the command will open that file in xml scheme, and it's not such friendly for users to change the configurations, since they don't know the exact meaning of each setting id.

vscode-java-pack extension now supports Java: Open Java Formatter Settings with Preview, which uses a custom editor to provide interactive editing experience of formatting settings.

It would be great if we merge the two entries into one and put the implementation into vscode-java repository, the interactive custom editor can replace currently plain xml to provide better experience, and we still remain a switch to open the profile in plain xml scheme for advanced users.

any thoughts? @fbricon @rgrunber @snjeza

Confronta il comando formatter-settings esistente in vscode-java con l’implementazione interattiva in vscode-java-pack, partendo dai rispettivi punti di ingresso del comando e dell’editor personalizzato. Il lavoro è completato quando i punti di ingresso sono consolidati, viene fornita la modifica interattiva del formatter e viene mantenuto un modo per aprire il profilo come XML semplice per gli utenti avanzati.