[BUGFIX] EXT:filelist Canceling the file exists already modal works now

When renaming a file with the name of an existing file a modal is shown.
Pressing the cancel button no longer renames the file with an unique name.

Resolves: #83624
Releases: master
Change-Id: I9963f6ce0b476f63043056d74e38af251ea0cd3e
Reviewed-on: https://review.typo3.org/55418


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Michael Oehlhof <typo3@oehlhof.de>
Tested-by: Michael Oehlhof <typo3@oehlhof.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Henning Liebe <h.liebe@neusta.de>
Tested-by: Henning Liebe <h.liebe@neusta.de>
Reviewed-by: Steffen Frese <steffenf14@gmail.com>
Tested-by: Steffen Frese <steffenf14@gmail.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>