[BUGFIX] FLUIDTEMPLATE cObj uses wrong template file

Due to some weird instance re-usage in the content object renderer,
the view object in FLUIDTEMPLATE content object must be re-created
for every call to render() to avoid some nasty cache issues.

Change-Id: If2ec0b171b8227aba9204d343a9e9010b69ecc78
Resolves: #44610
Related: #42182
Releases: 6.1, 6.0
Reviewed-on: https://review.typo3.org/17797
Reviewed-by: Marcus Krause
Reviewed-by: Oliver Hader
Tested-by: Marcus Krause
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn