[BUG] Error lines not displayed on windows

[Efratror]

bug:

Error lines are not displayed on Windows.

println("x") (without semicolon) should result in an error but non is shown

possible solution(s):

• Windows paths include a colon after the drive letter. In Diagnostics.ts the split position is hard-coded. Checking the OS-type and then setting the split position accordingly should solve the issue.
• When checking if the line includes the path due to windows using backslashes instead of forward slashes the check will always be false. Also make the path to check OS-dependent in the caller (parser.ts)