Run clang-tidy’s modernize-use-equals-delete pass

Adds a delete specifier on constructors, destructors or assignment methods that should never be called, ensuring they actually never will.

This is only the result of one clang-tidy pass, I will run other useful ones if this is actually something wanted by the project, such as the ones listed here: https://github.com/inkscape/lib2geom/pull/26