Add support for Fn swap for K400 Plus

Created by: correaa

K400 Touch seems to be supported but not K400 Plus, it might be a simple device recognition problem.

$ solaar --version
solaar 0.9.2
$ solaar show 3
  3: Wireless Touch Keyboard K400 Plus
     Codename     : K400 Plus
     Kind         : keyboard
     Wireless PID : 404D
     Protocol     : HID++ 4.1
     Polling rate : 8 ms (125Hz)
     Serial number: 43249AE8
        Bootloader: BOT 22.01.B0001
          Firmware: RQK 63.01.B0014
             Other: 
     The power switch is located on the top edge.
     Supports 24 HID++ 2.0 features:
         0: ROOT                   {0000}   
         1: FEATURE SET            {0001}   
         2: DEVICE FW VERSION      {0003}   
         3: DEVICE NAME            {0005}   
         4: WIRELESS DEVICE STATUS {1D4B}   
         5: RESET                  {0020}   
         6: BATTERY STATUS         {1000}   
         7: REPROG CONTROLS V4     {1B04}   
         8: SWAP BUTTON            {2005}   
         9: NEW FN INVERSION       {40A2}   
        10: ENCRYPTION             {4100}   
        11: KEYBOARD DISABLE       {4521}   
        12: TOUCHPAD RAW XY        {6100}   
        13: GESTURE 2              {6501}   
        14: DFUCONTROL 2           {00C1}   
        15: unknown:1811           {1811}   internal, hidden
        16: unknown:1830           {1830}   internal, hidden
        17: unknown:1890           {1890}   internal, hidden
        18: unknown:1DF3           {1DF3}   internal, hidden
        19: unknown:1E00           {1E00}   hidden
        20: unknown:1EB0           {1EB0}   internal, hidden
        21: unknown:1861           {1861}   internal, hidden
        22: unknown:18B0           {18B0}   internal, hidden
        23: unknown:1F11           {1F11}   internal, hidden
     Battery: 90%, discharging.
 $ solaar config 3
solaar: error: no settings for Wireless Touch Keyboard K400 Plus