Mac: file events are not reported when using workspace path with different casing (fixes #1426) (#19918)

* Mac: file events are not reported when using workspace path with different casing (fixes #1426)

* fix test on linux

* more fixes

Fixes #19375
Related #19863

Fixes #19863
Related #19375

The setting will now correctly open a new window when no file is specified, but if
a file is specified it will reuse. This is so opening via the file manager will reuse
the window.

Fixes #19775

- Do not use scheme for files
- Use scheme for non files

Fixes #19740: Find and replace capture group/backreference inserts `undefined` instead of empty string