TISTUD-6598 var declarations on newlines should not all be placed on a single line

I managed to finally hack the JS formatter to do this, and set the default to this being on.

We essentially enforce a newline between variables attached to the same var statement, and then on those pushed to a newline, we add 4 spaces to align the var names.
Note that this is explicilty 4 spaces, and doesn't try to get fancy about trying to use indents (may may user tabs or spaces and may vary in length).