test: test for listing files only

tests/cmd/only_file_unix.stdout

@@ -0,0 +1,19 @@
+a
+b
+c
+d
+e
+f
+g
+h
+i
+image.jpg.img.c.rs.log.png
+index.svg
+j
+k
+l
+m
+n
+o
+p
+q

tests/cmd/only_file_unix.toml

@@ -0,0 +1,2 @@
+bin.name = "eza"
+args = "tests/itest --only-files"