Update debugger to 1-18-0
Update debugger to 1-18-0

Among other changes, this includes:
* Backend support for set next statement
* Fixes for string functions in conditionally breakpoints
* Improvements to browser launch.json schema

gregg-miskelly/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,OmniSharp/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode