[ticket/12063] Remove obsolete valign attributes from tr tags

PHPBB3-12063
[ticket/12063] Usee CSS to replace valign=top

I found that inline styling was used quite a bit as the replacement to
valign=top already
throughout the style files. I’m sticking to that practice, rather than
reinventing the wheel.

PHPBB3-12063
Merge remote-tracking branch 'vsephpbb/ticket/12063' into develop

* vsephpbb/ticket/12063:
  [ticket/12063] Usee CSS to replace valign=top
  [ticket/12063] Remove obsolete valign attributes from tr tags