allow disabling dscanner usage entirely via configuration

[thinkingerrol]

For example, right now everything is squiggly if you use expression-based contract syntax, because of dscanner 0.5.8 embedded as a library.

[LaurentTreguier]

It's already possible, you simply don't have the option because you have an outdated version of vscode-dls. have you tried the good old "uninstall and reinstall" to try and see which version VSCode installs ?