Centers all elements in the parents bounds taking care of the text content

This changes check the content of title and subtitle to aligns those texts vertically in the pull to refresh view.

Taking the maximum of the width of those 2 labels + the width of the arrow and the margin between texts and arrow, we compute the width of the whole content to center it horizontally in the parent's view bounds.

As you suggested last day, you should probably wnat to compute the width of the labels cross state to take the max one and use this max width to center the whole content. So that, the left arrow will not move horizontally depending on the state of the pull to refresh ...