RactangeShape setSize and constructer alternatives

Currently RactangeShape's setSize and constructor only take Vector2f, this is inconsistent with other things this shape can do, for example setPosition can take a Vector2f  or 2 floats. It can also lead to more/messier code while working with RactangeShape in an SFML project/game.  I've added alternate methods so that RactangeShape's setSize and constructor also accept 2 floats.