refactor: add namespaces for features

[FlayaN]

Added namespaces for all features.

Each namespace is added in its own commit, so this PR can be merged without squash if wanted.

To see changes done hide the whitespace changes

[doodlum]

This is really cool. I think what we could do is in another PR at some point, the same for include files. That way we know where things come from and don't share a global scope. E.g. M_PI becomes Constants::PI

[FlayaN]

This is really cool. I think what we could do is in another PR at some point, the same for include files. That way we know where things come from and don't share a global scope. E.g. M_PI becomes Constants::PI

Yeah that is the plan, just wanted to do it for features to start with!