Refs: microsoft/vscode#105771

I noticed that we introduced quite some settings for debug.javascript while most of this make perfect sense I just wanted to share my thoughts that:

• The less settings the better
• No need to intrdouce a setting only if a couple of users ask for it. Nobody will always be happy.
• Less settings, less complexity
• We depracte the "use preview" settings once things go out of preview

I did not really review all of them but there are some quite obscure ones, like for example
"debug.javascript.warnOnLongPrediction"

Just my 2 cents.