Fix creative tabs with search displaying all enchanted books. Fixes #1301

Additionally adds the ability to give a custom width for the search box, in case of longer creative tab names.
I was suggested to explain this piece of code because it could be confusing or not clear what it is doing.

Line 130: sets the width of the text field to the value the creative tab says it should be (defaults to 89, which is the normal value of the search bar)
Line 131: sets the X position of the text field to be the X offset of the GUI + 171 - the newly set width of the text field.

171 = 89 + 82; 82 being the normal offset of the search box when the width is 89.