Investigate if the current language server module abstraction fits our needs

We don't need these overrides as we register the request handlers in a singlemodule QQmlHighlightSupport. This is an unusual pattern because QQmlBaseModule
and QLanguageServerModule abstractions are designed to handle a single module which has a single request handlers. That is not the case for the semanticTokens module which has a one server module but also has three different handlers.

Investigate and try to isolate QQmlBaseModule::process() from qlanguageservermodule class.