[TASK] Make progress of tasks in scheduler more readable

Currently it's hard to read the progress of tasks in the
scheduler due to the combination of blue, white and light
grey. Change of background color for progress from f5f5f5
to dedede makes it more readable.

Resolves: #79844
Releases: master

Change-Id: I896e66452e3093d729522c9ca7da6b597e0451c7
Reviewed-on: https://review.typo3.org/51710


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Tomas Norre Mikkelsen <tomasnorre@gmail.com>
Reviewed-by: Philipp Gampe <philipp.gampe@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Sascha Egerer <sascha@sascha-egerer.de>
Tested-by: Sascha Egerer <sascha@sascha-egerer.de>