Shadow processes running in a container

[jouve]

This is a feature idea.

Similar to #1036, but instead of hiding the processes, I'd prefer to have them "shadowed".

It would be similar to current option "Shadow other users' processes", but for containers.

Wdyt ?

[BenBE]

One of the side effects of hiding those processes is that htop does not query a bunch of information of those processes. This optimization would be lost if those processes remain visible …