Add new mount option to allow bind mounting symlinks

[giuseppe]

Currently, when attempting to bind mount a volume onto a path that is a symlink, crun resolves the symlink and mounts the volume onto the symlink's target. This behavior is not always desirable, as discussed in containers/podman#25947.

This issue proposes the addition of a new mount option in crun. This option would allow users to specify that if the mount point is a symlink, the bind mount should occur over the symlink itself, rather than its target. This would be analogous to using O_NOFOLLOW or RESOLVE_NO_SYMLINKS when opening or resolving paths.