Lexically rename variable changes the screen position dramatically (and shouldn't have to)

[adamk]

In the current implementation, the "Lexically Rename Variable" function results in a long wait to parse the document (which is not a big deal) followed by a dramatic snap to a new focus and line (which is really annoying).

The Lexically Rename Variable function inherently should never change the line quantity or the position of any code. As a result, we SHOULD be able to remember and keep the position of the editor at the time of the Lexical Rename Variable menu entry being fired and keep it at the end of the replacement.

[zenogantner]

note: The current name of this function in the "Refactoring" menu is "Rename Variable".

[zenogantner]

Also annoying: After you undo a rename, the focus is at the end of the document.