Support non-touch device to choose file or folder (#8696)

## Background
`pathchooser.lua` does not support non-touch device to choose file or folder due to those device cannot generate long press event.

## Choose File
Non-touch device can select file in list, it is good enough to choose file without long press to confirm.

## Choose Folder
`pathchooser.lua` changes the label of current directory `.` to `Long-press to choose a folder`. It is user friendly, while for non-device, it is a very good place to let user tell the system I want the current folder to be chosen without extra long press.

frontend/ui/widget/pathchooser.lua

@@ -1,5 +1,6 @@
 local BD = require("ui/bidi")
 local ButtonDialogTitle = require("ui/widget/buttondialogtitle")
+local Device = require("device")
 local FileChooser = require("ui/widget/filechooser")
 local UIManager = require("ui/uimanager")
 local ffiutil = require("ffi/util")
@@ -51,6 +52,9 @@ end
 function PathChooser:onMenuSelect(item)
     local path = item.path
     if path:sub(-2, -1) == "/." then -- with show_current_dir_for_hold
+        if not Device:isTouchDevice() and self.select_directory then -- let non-touch device can select the folder
+            return self:onMenuHold(item)
+        end
         -- Don't navigate to same directory
         return true
     end
@@ -68,6 +72,9 @@ function PathChooser:onMenuSelect(item)
         return true
     end
     if attr.mode ~= "directory" then
+        if not Device:isTouchDevice() and self.select_file then -- let non-touch device can select the file
+            return self:onMenuHold(item)
+        end
         -- Do nothing if Tap on other than directories
         return true
     end