You will be given a simple string expression representing an addition or subtraction in 8-bit 2's complement arithmetic. Write a function that returns the result in base 10 followed by a binary representation. If any of the values are outside the range of 8-bit 2's complement, return "Overflow".
eight_bit("3 + 12") ➞ (15, "11 + 1100 = 1111")
eight_bit("3 - 12") ➞ (-9, "11 - 1100 = 11110111")
eight_bit("-18 - 6") ➞ (-24, "11101110 - 110 = 11101000")
eight_bit("65 + 70") ➞ "Overflow"
eight_bit("-127 + 127") ➞ (0, "10000001 + 1111111 = 0")
Numbers in 8-bit 2's complement notation can range from -128 to 127. The eighth (leftmost) bit signifies a negative number.