[FEATURE] Add basic file search in element browser

Releases: master
Resolves: #69120
Change-Id: I500f4979edebff52a002518189c69acc222e6e65
Reviewed-on: http://review.typo3.org/43503


Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Maier <dani-maier@gmx.de>
Reviewed-by: Daniel Maier <dani-maier@gmx.de>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>