[!!!][FEATURE] Streamline Fluid Styled Content and CSS Styled Content

CSS Styled Content has been a long time the preferred way of rendering
content in the frontend. Fluid Styled Content was introduced as
successor of CSC, but the feature set diverged from the beginning. The
lack of flexibility and incomplete feature set in comparision to CSC
made it hard to migrate existing instances.

Since TYPO3 CMS 7.6 Fluid-Templates are the defined standard and
official recommendation for content rendering. The feature set of FSC is
now matching CSC. Both content renderings are now streamlined to be
fully compatible with each other. For the period of CMS 8 LTS CSC will
share the same capabilities to make an transition as easy as possible.
CSC is now deprecated and goes into maintenance mode and will be removed
with CMS 9.

For compatibility, CSC is now supporting Textmedia that was before
exclusive to FSC. But also FSC has learned some tricks from CSC. Fluid
Styled Content has now support for all content elements prior existing
only in CSC, this includes "Text", "Text and Images" and "Images". Also
for example "Frames", "Space before" and "Space after" are now again
featured across both content rendering methods.

Releases: master
Resolves: #79622
Resolves: #72422
Resolves: #75466
Resolves: #71570
Resolves: #71484
Change-Id: I7d2a9072baad508b6b87470b847444b91e7323fb
Reviewed-on: https://review.typo3.org/51065


Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>