[RTL UI] Bidi-wrap filenames, paths, urls, metadata

bidi.lua:
- Revert "Alias everything to Bidi.nowrap() when in LTR UI,
  as using LTR isolates seems uneeded when already LTR" (part
  of a628714f) which was a wrong assumption: we need proper
  wrappers for all things paths. Enhance some of these wrappers.
- Fix GetText RTL wrapping which was losing empty lines and
  trailing \n.

- Wrap all paths, directories, filenames in the code with
  these wrappers.
- Wrap all book metadata (title, authors...) with BD.auto(),
  as it helps fixing some edge cases (like open/close quotation
  marks which are not considered as bracket types by FriBiDi).
  (Needed some minor logic changes in CoverBrowser.)

- Tweak hyphenation menu text
- Update forgotten SortWidget for UI mirroring
- KoptConfig: update "justification" index for RTL re-ordering,
  following the recent addition of the page_gap_height option.

frontend/device/android/device.lua

@@ -142,9 +142,10 @@ function Device:init()
                     -- we cannot blit to a window here since we have no focus yet.
                     local UIManager = require("ui/uimanager")
                     local InfoMessage = require("ui/widget/infomessage")
+                    local BD = require("ui/bidi")
                     UIManager:scheduleIn(0.1, function()
                         UIManager:show(InfoMessage:new{
-                            text = T(_("Opening file '%1'."), new_file),
+                            text = T(_("Opening file '%1'."), BD.filepath(new_file)),
                             timeout = 0.0,
                         })
                     end)
@@ -255,7 +256,8 @@ function Device:retrieveNetworkInfo()
     if ip == "0" or gw == "0" then
         return _("Not connected")
     else
-        return T(_("Connected to %1\n IP address: %2\n gateway: %3"), ssid, ip, gw)
+        local BD = require("ui/bidi")
+        return T(_("Connected to %1\n IP address: %2\n gateway: %3"), BD.wrap(ssid), BD.ltr(ip), BD.ltr(gw))
     end
 end