Add .nextElementSibling and .previousElementSibling properties to DOM Element that point to sibling elements.

• nextElementSibling
• previousElementSibling

Tested in search and list methods, scoreText shows ' Rated 4.3 stars out of five stars ' instead of 4.3

Issue description

The original title key translates the title. It should not.

Version of IMDbPY, Python and OS

• Python: 3.6.9
• IMDbPY: 6.9dev20200125 (installed from the repo here)
• OS: uname_result(system='Linux', node='blackfx', release='4.15.0-76-generic', version='#86-Ubuntu SMP Fri Jan 17 17:24:28 UTC 2020', machine='x86_64', processor='x86_64')