Featur request: btrfs rescue should always print a summary line for clarity

[attila123]

I needed to use "btrfs restore" to restore data from an unmountable btrfs filesystem.
As a first time user of "btrfs restore" I got confused about "btrfs restore", did a dry run, and it
just output about a dozen errors about some files, and I thought
that's it, no files can be restored.
Then I tried it with other options, especially -v shown me that the
majority of the files can be restored. I consider myself an
intermediate GNU plus Linux user, yet given the stressful situation of the filesystem corruption
and being a first time user (btrfs n00b) I missed experimenting with
the -v option in the first phase.

So I propose that "btrs restore" should always print a summary line at
the end to make it more user friendly (e.g. also for the first time users).
Something like this:

"x files restored in y directories[, total size of files is z ]. Use -v command line option for more
information."

The part in square bracket is optional / nice to have, might be useful
e.g. to estimate the required free space in the target filesystem.