modified RotaryEncoder MicroPython driver

[zerovijay]

written in pep 8 style and added error handling for if any one of a pin not provide. and class functions switch_detect,
call_handlers and rotary_change now private also unwanted sum variable the variable only for class. now that variables
are private. also the class __init__ have a object holder we can pass the Pin class directly on the holders like

encoder = RotaryEncoder(
   dt_pin=Pin(0, Pin.IN, Pin.PULL_UP),
   clk_pin=Pin(0, Pin.IN, Pin.PULL_UP),
   sw_pin=Pin(0, Pin.IN, Pin.PULL_UP),
)

or

# Define pins for the rotary encoder
dt_pin = Pin(0, Pin.IN, Pin.PULL_UP)
clk_pin = Pin(1, Pin.IN, Pin.PULL_UP)
sw_pin = Pin(2, Pin.IN, Pin.PULL_UP)

# Create a RotaryEncoder object
encoder = RotaryEncoder(dt_pin, clk_pin, sw_pin)

both are valid. This allow us to pull_down or pull_up the GPIO internal resister. this simple efficient.
not fancy way.
But i notes something on the class if any one of a state like CW or CCW run fast enaph the program face scheduling
error.