Add movement functions for 7-Segment Displays

[noah1510]

At the moment the movement functions only work if you use an LED Matrix.
It would be nice to have the option to also move data when you have 7-Segment Displays connected.
The following points are what needs to be done in order for this to work.

• add a 7-Segment-Mode config option (boolen, default false)
• move the current movement function into LedController_movement_matrix.hpp
• create LedController_movement_7_Segment.hpp and implement those movement functions (eg. moveLeft_7_Segment)
• rename functions in LedController_movement_matrix.hpp (eg. moveLeft to moveLeft_matrix)
• implement old function name in LedController_movement.hpp (eg. moveleft calls moveLeft_Matrix or moveLeft_7_Segment depending on the config)
• make LedController_movement_matrix.hpp and LedController_movement_7_Segment.hpp private
• update movement documentation
• write 7-Segment Documentation page
• update controller_configuration page and usage page
• write unit test
• write example

If you think that anything is missing feel free to mention it, I will add it to the list.
The list might change in the future depending on how the implementation will work out.