joy2key,wifi: add an on-screen keyboard dialog

Currently, the WiFi configuration from RetroPie menu needs a keyboard for configuring a connection.
Added a `python` script to display on-screen keyboard which can be operated with `joy2key` and the gamepad, which allows entering the WiFi network/key/password without a keyboard.

The script accepts keyboard input, so it's suited for both keyboard and joystick input. It's using the `urwid` library (https://urwid.org).

The WiFi scriptmodule was modified to use the new OSK script instead of the `dialog` based inputboxes.

Additional modifications to the WiFi module:
 - added a confirmation step before removing the WiFi config and stopping the WiFi
 - added an info message during the WiFi scanning (instead of having a black screen)
 - removed the check for the pass length, it's done by the new OSK script
 - reformatted a bit the 'country' warning

NOTE: I've tested the new OSK script with smaller displays, but anything less than 40 cols will not be displayed fully. The OSK keyboard will scroll horizontally (when there's no more space on screen), but this is non-intuitive and might confuse users. _If_ we need to accomodate an even smaller screen size, then the OSK display area should be probably changed to accomodate that (i.e. less letters on a 'keyboard' row).

Author: cmitu

scriptmodules/admin/joy2key.sh

@@ -15,11 +15,11 @@ rp_module_section="core"
 
 function _update_hook_joy2key() {
     # make sure joy2key is always updated when updating retropie-setup
-    rp_isInstalled "$md_id" && install_bin_joy2key
+    rp_isInstalled "$md_id" && rp_callModule "$md_id"
 }
 
 function depends_joy2key() {
-    local depends=()
+    local depends=(python3-urwid)
     # 'python3-sdl2' might not be available
     # it's packaged in Debian starting with version 11 (Bullseye)
     local p_ver
@@ -33,7 +33,7 @@ function depends_joy2key() {
 
 function install_bin_joy2key() {
     local file
-    for file in "joy2key.py" "joy2key_sdl.py"; do
+    for file in "joy2key.py" "joy2key_sdl.py" "osk.py"; do
         cp "$md_data/$file" "$md_inst/"
         chmod +x "$md_inst/$file"
         python3 -m compileall "$md_inst/$file"