Styling tweaks for inline interwiki search

Styling tweaks for inline interwiki search

To make this look reasonable had to adjust the other styling around
it, I think this now makes more sense too

* moved p tag top margin to .searchresults, the only p tag is at the top
  of search results anyways,
* moved the left margins on every element inside .searchresults
  to .searchresults for consistency
* removed bottom padding from .searchresults p completely, this is
  unnecessary. The top margin of .mw-search-results (.3em) along
  with the bottom margin of generic p tags (.5em) is plenty on its own
* strip the top margin on mw-search-interwiki-header when it comes
  immediatly after .mw-search-nonefound for better spacing to match
  mockup

Bug: T112349
Change-Id: I3dec110e1ac0ab9c3dab1a3f7e6c2b747f2e28c8