Offer an opton to only annotate the stack frame boundaries and not the stack variables

[xusheng6]

Right now, we have the debugger.stackVariableAnnotations setting which annotate the stack variable with the help of the analysis info. However, it could be inaccurate at times, and the user may wish to disable it. That said, the stack boundaries are less prone to errors, and I believe it would be helpful in most cases. So it would be nice if we can offer a different setting that controls whether we mark up the stack frame boundaries