SFML 3 Code Fixes

[eXpl0it3r]

Tracking reported SFML 3 code issues to be solved at one point.

• sf::ContextSettings missing aggregate initialization: https://www.sfml-dev.org/tutorials/3.0/window/opengl/#creating-an-opengl-window
• Fix loadFromSamples example code, see docs(v3): usage of loadFromSamples is wrong #259
• sf::IpAddress isn't an std::optional, see https://en.sfml-dev.org/forums/index.php?topic=29865.0

Leave open for a while

[CosminPerRam]

Should #259 also be in this list?