Rename Project Euler directories and other dependent changes (#3300)

* Rename all Project Euler directories:

Reason:
The change was done to maintain consistency throughout the directory
and to keep all directories in sorted order.

Due to the above change, some config files had to be modified:
'problem_22` -> `problem_022`

* Update scripts to pad zeroes in PE directories

project_euler/problem_016/sol2.py

@@ -0,0 +1,30 @@
+"""
+Problem 16: https://projecteuler.net/problem=16
+
+2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
+
+What is the sum of the digits of the number 2^1000?
+"""
+
+
+def solution(power: int = 1000) -> int:
+    """Returns the sum of the digits of the number 2^power.
+
+    >>> solution(1000)
+    1366
+    >>> solution(50)
+    76
+    >>> solution(20)
+    31
+    >>> solution(15)
+    26
+    """
+    n = 2 ** power
+    r = 0
+    while n:
+        r, n = r + n % 10, n // 10
+    return r
+
+
+if __name__ == "__main__":
+    print(solution(int(str(input()).strip())))