[utils] Scale a copy of the geometry in polygon_patch - #2198

polygon_patch scaled the polygon to absolute coordinates in place. A caller passing an array it keeps, e.g. create_obj_patch(word.geometry, page.dimensions) for a rotated word, got its relative geometry overwritten with pixel coordinates, and a second call scaled it again:

>>> geometry = np.array([[0.1, 0.1], [0.4, 0.1], [0.4, 0.2], [0.1, 0.2]])
>>> create_obj_patch(geometry, (100, 200))
>>> geometry
array([[20., 10.], [80., 10.], [80., 20.], [20., 20.]])

The patch is now built from a scaled copy, so the geometry passed in stays relative. Page exports store geometries as tuples, so visualize_page was not affected, and the patches are the same as before