adding compileOnOpen setting option

[joennlae]

First of all, thank you for this awesome VSCode extension 💯

I think the option compileOnOpen should enhance the experience. It can, when one uses verilator for example, completely replace the ANTLR e.g. verifyOnOpen option.

I used it with launchConfigurationVerilator where I add my import paths with -I.

Cheers
Jannis