[TYPO3-core] Hardcoded linebreak after each radio element

[Sebastian Kurfuerst]

Hi Michael,
we already talked about this some times - The hardcoded <br> was in
TYPO3 forever - and is as well used in the current version. Ernesto once
suggested to change this, but we rejected his patch for now as it
changes a lot of stuff concerning the TypoScript configuration - and to
make sure everything still works correctly he would have introduced a
big compatibility layer - which was not worth it.

We decided to fix it if somebody reports it, but postproning this after 4.0.
Hope that refreshes your mind :)
Greets, Sebastian