Add solution for Project Euler problem 67 (#5519)

* New solution for Euler problem 67

A faster and memory efficient solution based on the template of sol1.py.
Modified the solution to be more memory efficient while reading and generating the array
and during the solution finding.
No conditions and straightforward logic.

* added return type hint

* Update project_euler/problem_067/sol2.py

Preferring comprehensions over map

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update sol2.py

Self explanatory variable names

* Updated sol2 to problem 067 in directory

* Update project_euler/problem_067/sol2.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Update project_euler/problem_067/sol2.py

Co-authored-by: Christian Clauss <cclauss@me.com>

* Fixed extra line

Co-authored-by: Christian Clauss <cclauss@me.com>