Attempt to automatically de/reference symlinked files

[connor4312]

Currently for Node we sometimes require people to pass --preseve-symlinks (and document this) since Node dereferences scripts it loads, which can cause file paths to not patch up.

However we could also use fs.realPath to dereference them ourselves. Breakpoints should be applied in both places (since we won't know which is the right one ahead of time). Still need to figure out how to deal with loaded sources, however, since when a source loads we need to tell VS code the path it knows about rather than the real path.

[restjohn]

Hi @connor4312. Is the VS Code team actively working or planning to work this issue? Do you have any insight on whether debugging works with NPM 7's workspaces? I would imagine projects that adopt workspaces might run into this same unbound breakpoint problem, but I have not yet had an opportunity to test it myself, so that's just my speculation for now. Hopefully I'll get some time to test that soon, though.