don't draw separator line if we cannot compute relationship properly for all lines (important in case of process input — nodejs for example)

(cherry picked from commit 632d4c869c1abbaddc52f42dab3285fec8f611aa)
WEB-11690 TypeScript breakpoint is not hit
We must respect fs case sensitivity
sourcemap visualizer: ugly compiler can produce mappings for empty lines, and IDEA can then strip whitespace from line ends, but sourcemap still references to empty ranges

(cherry picked from commit 2fde908ae4f7483345260e2422fe181489c5f09d)