TOC: Use padding instead of inline-block for space

TOC: Use padding instead of inline-block for space

The padding does not get reduced on table cell size adaption. See T126857.

The padding is also visible for IE7 and lower.
c7894deb used an inline-block because it get ignored by IE7 and lower.
Now the gap between tocnummber and toctext is 0.5em + one space for IE7 and lower.
This is acceptable.

The additional CSS selectors are necessary to get the padding on the correct side.
* On Special:EditWatchlist and
* On content pages with a user interface language with different direction.

Bug: T126857
Change-Id: I61e3835f28cd65152cf7920a17e393dc68b76e41