Show when an incomplete search has take place

Broot stops searching when it has found enough results to fill the screen. This is reasonable behaviour and plays to the tool's strength. However, broot can in some cases search all paths and it typically informs the user when it has truncated a listing.

As the tool currently presents listings, it is ambiguous whether or not the results shown to user are complete or if broot has just stopped searching. broot should present when paths are completely or incompletely searched to prevent this ambiguity.

I though of 3 different ways to present this information:

• A string after the directory name
• A list item in the listing, though this has the downside that it clutters up the view quite a bit
• Re-using ellipses for this purpose instead of the currently (probably buggy) behaviour, see #1214

/home/user/project
 ├──src
 │  ├──main 10 items not searched
 │  │  ├──search.rs
 │  │  └──2 unlisted
 │  ├──util
 │  │  └──searchlib.rs
 │  │  └──10 items not searched
 ├──doc …
 │  ├──search …
 │  │  └──searching-and-finding.md
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search                                                                  h:n  gi:y