Fixes #24209

**Bug**
Currently, for the js/ts references code lens, even if there are zero references you can click on the lens. This display an empty peek view

**Fix**
Allow code lenses to only register a title for the lens with no actual backing command

introduces more changes to the SCM api

fixes #23623
fixes #23676

debt - no guessing-caching, better use of gc-signals, command converter using gc-signals, main side heap service

* a declared module allows to have a sibling module containing experimental API
* this change also cleans up some bogous type pollution that happened because vscode used to be both, a declare module and a global namespace

let plugin host commands internally also accept ICommandHandlerDescriptions and have a way to get them all

# Conflicts:
#	src/vs/languages/html/common/htmlTags.ts