tables: remove special setting for caption .actions:not(:empty) since it won't work in almost all possible cases, adjust some templates for this case to avoid layout glitches, re #3767, rerefines [29118]

git-svn-id: svn://develop.studip.de/studip/trunk@29205 c5b85792-5220-0410-ad23-ed5b6b8ad999