[!!!][TASK] Remove unused downloadname from sys_file_reference

The field sys_file_reference.downloadname was added with FAL
but never touched or used (nor has it a TCA definition) and is now
removed.

Resolves: #74124
Releases: master
Change-Id: I6ce886fe1e05f30d625b65d5c44fa12c2f523fd7
Reviewed-on: https://review.typo3.org/47088


Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>