[BUGFIX] EXT:form - avoid number reduction in currency filter

Avoid a number reduction each time the filter is applied.
Preserve the decimal places.

Resolves: #69807
Releases: master
Change-Id: I1aed27489ea9a7b7d1f3a3e593803bf075ea25a9
Reviewed-on: https://review.typo3.org/43475


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>