[BUGFIX] Install css_styled_content by default

As felogin and some other extensions don't work without
css_styled_content it should be enabled by default as well. This patch
adds the Package class to install the extension by default.

Resolves: #56292
Releases: 6.2
Change-Id: I9aad88966c0c292cdff865276dc131f358a52697
Reviewed-on: https://review.typo3.org/27858
Reviewed-by: Dmitry Dulepov
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Nicole Cordes
Tested-by: Nicole Cordes
Reviewed-by: Christian Kuhn
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind