Performance issues from slow filesystem responses

When lf displays directories, it normally gathers the file information before listing everything. However, when one of the directories is a mounted network share with a low bandwidth (or just busy with an operation), this can significantly delay the display and freeze the ui for several seconds.

To reproduce:

simply mount a sftp mount with sshfs and copy a large file to the mounted share. The start lf in the parent directory that would list the mounted share as one of many files. Lf now waits before displaying anything until it can gather the information from the share, like the number of files inside, leading to multiple second ui freeze.