[fs-watcher] not support soft link watch

[502647092]

Description

fs-watcher not support soft link watch

Reproduction Steps

OS and Theia version:
git-commit: 9105c43

Diagnostics:

[akosyakov]

Unfortunately nsfw reports an event only for one symlink, not all :( We've decided to resolve all symlinks to real paths: #2566 (comment) It covers most of the cases. But obviously we cannot report for all symlinks, since we don't have such information. Also see Axosoft/nsfw#30, implementing it via indexing all symlinks will harm performance

[akosyakov]

As an idea we could try to preserver an information whether the given file node is a symlink or not and to which realpath and refresh it as well when an event is reported. I remember trying something like that but it would fix an issue only for the navigator and design was quite impactful to apis.

[havogt]

I probably encountered this bug with a gitpod setup. I didn't want to enforce .theia/settings.json for the non-gitpod users, so I decided to put the .theia folder in a subdirectory and create a symlink on gitpod init. The effect is that in the debug view, the launch selector doesn't get updated if a new configuration is added to the launch.json file.
Here is an example setup to reproduce: https://github.com/havogt/gitpod-playground.
Not high priority for me, as I solved the problem with hard links.