Use semantic token provider

[mark-wiemer]

Is your feature request related to a problem? Please describe. It's hard to differentiate between parameters and other local variables because they're the same color

Note x and y are the same color in the below example

test(x) {
    y = 2
    return x + y
}

Describe the solution you'd like Use semantic highlighting as described in VSCode's semantic highlighting guide

Describe alternatives you've considered I can't change the colors myself, but I have been naming parameters differently to distinguish. This is annoying.