Migrate to C++17; refactor Strategy pattern

[hextriclosan]

• Let's migrate to the C++17 standard - it's 2022
• Strategy pattern refactored (modernized)
  • raw pointers changed to smart pointers
  • algorithms are simplified
  • some names are fixed to camelCase

[neochief]

Thanks a lot! If you want to do a similar modernization to other patterns — feel free to proceed. Thanks!

[hextriclosan]

Thanks a lot! If you want to do a similar modernization to other patterns — feel free to proceed. Thanks!

great! I will do it in some time