[BUGFIX] Supply setter for bodytag in ModuleTemplate

It is convenient to be able to set a custom body tag in a module.
While we're at it... let's add one at all

Resolves: #71349
Releases: master
Change-Id: I37b800709ee049f460352b93fafe1185b40252b7
Reviewed-on: https://review.typo3.org/44554


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>