The phrase 'in the world' has been used to intensify the meaning after superlatives and words such as all, any, everything etc for the past 1,000 years!
"I would give everything I own in the world in order to..."
"He is one of the four finest goalkeepers in the world."
These are just illustrations of the point. As regards 'all the time in the world' that simply suggests that the time available is utterly limitless. Of course, it isn't in reality, but it is a nice figurative way of expressing the thought.