Add ics manager command line app

[iory]

No description provided.

[708yamaguchi]

$ ics-manager 
Traceback (most recent call last):
  File "/home/naoya/.local/bin/ics-manager", line 5, in <module>
    from rcb4.apps.ics_manager import main
  File "/home/naoya/ros/kxr/src/rcb4/rcb4/apps/ics_manager.py", line 8, in <module>
    from rcb4.ics import ICSServoController
  File "/home/naoya/ros/kxr/src/rcb4/rcb4/ics.py", line 6, in <module>
    import readchar
ModuleNotFoundError: No module named 'readchar'

[iory]

--- Servo Status ---
>> Current Servo ID: 17 -> Next Servo ID: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ]
   Angle: 7504
   Baud Rate: 1.25Mbps
   Rotation Mode: Disabled
   Slave Mode: Disabled
   Reverse Mode: Disabled
   Serial Mode: Disabled
   Free: Disabled
----------------------

Use ↑↓ to navigate, ←→ to adjust Current Servo ID or Servo Angles
Press 'Enter' when Current Servo ID is selected to save the currently highlighted ID in green.
Press 'z' to reset servo position
Press 'r' to toggle rotation mode (enables continuous wheel-like rotation)
Press 'f' to set free mode

'q' to quit.