feat: enhance --mounts: display mount root path

[vlad20012]

The path of mount root is now printed in square brackets next to a mount source, similar
to findmnt command output. The root is not displayed if it equals to /.

Example:

mkdir /foo && mkdir /bar;
mount --bind /bar /foo
eza -l --mounts /
# /bar
# /foo [/dev/sda1[/bar] (ext4)]
# ...
findmnt /foo
# /foo /dev/sda1[/bar] ext4   rw,relatime,errors=remount-ro

This is useful for mount --bind as well as for mounts of non-default btrfs subvolumes.
Linux only.

[cafkafk]

Thanks, this is pretty cool. One thing I do think would be nice before merge is if the mounts would be aligned on the grid (and respect the --header flag as well). Currently, the mounts are unaligned.

E.g. see:

$ eza -l / --mounts --header --no-permissions --no-user --no-filesize --no-time

Name
bin
boot [/dev/nvme0n1p1 (vfat)]
dev [devtmpfs (devtmpfs)]
etc
home [zpool/home (zfs)]
lib
lib64
mnt
nix [zpool/nix (zfs)]
opt
proc [proc (proc)]
root
run [tmpfs (tmpfs)]
rustup
srv
sys [sysfs (sysfs)]
tmp [tmpfs (tmpfs)]
usr
var [zpool/var (zfs)]

[vlad20012]

@cafkafk I agree, indeed it would be much better if mounts are aligned. But I don't add mounts in this PR. They were added in #167, and they was unaligned there. So I believe alignment should be done in a separate PR.

[vlad20012]

@cafkafk Oh wait, after some thought, it began to seem to me that mount are rather similar to symlik destinations. And symlinks destinations seems not aligned in both ls -l and eza.

So, do you really think mounts should be aligned regardless?

[gierens]

@vlad20012 Code and functionality looks fine to me! Thanks! ... @cafkafk regarding the alignment, I think this would unnecessarily complicate this PR ... I'd rather see this in a separate PR that then might also tackle the missing alignment of symlink targets.

[vlad20012]

@cafkafk,
Hi! Just a friendly ping - would love your thoughts when you have a moment. I’d really appreciate it if we could get this PR merged. Thanks!