[lsp] Same variable syntax highlight over-highlighting variables

[johnnycheng0210]

Issue

When clicking a variable in a ts file, it will highlight all variables of the same name even if it is not the same variable. In the existing typescript plugin, it will only highlight the correct instances of the variable

In the attached example, when clicking bar in tsgo extension, both bar will be highlighted, whereas in the existing ts plugin, only one would be highlighted.

function foo(){
    let bar;
}

function baz(){
    let bar
}

[jakebailey]

This is "document highlight", a call we haven't implemented yet, so what you get at the moment is VS Code's default word highlighting. This is going to be worked on very soon.