Backspace to delete an element which is at the end of list - <li> element

Steps to produce bug:

1. Create a page.
2. In the editor, create a bullet list.
3. Enter some text and click enter. A second bullet point is created.
4. Insert a random text and insert an element which has nodeType=1 after that. Ex: Element has nodetype=1 a bold text or icon emotion icon
5. Make sure there is no any element, even spaces (hidden_char, no_break_white_space,   ...), after the element (nodeType=1)
   Sometimes you should press DELETE key to make sure there is no hidden space after the element (nodeType=1) or may use Developer Tool of browser to inspect DOM and make sure the nodeType=1 is the last of line.
6. Try to put cursor after the element (nodeType=1).
7. Press backspace to delete the element (nodeType=1)
8. Backspace works incorrectly: the cursor jumps at the beginning of <li> and the remove <li> element
   Expect: When pressing backspace key should remove the element before cursor (in this case it is the element nodeType=1)

Related ticket: https://jira.atlassian.com/browse/CONFDEV-21873