[SECURITY] Escape output of tt_content.default

Escape the value of the field CType in tt_content.default.

Resolves: #73450
Releases: master, 7.6, 6.2
Security-Commit: fa4f42b5e20e08fa154be29de867e1c01d4f7e1c
Security-Bulletins: TYPO3-CORE-SA-2016-005, 006, 007, 008
Change-Id: Iaa185caac5e08d3ba03121b45edca2fd98afa741
Reviewed-on: https://review.typo3.org/46835


Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Oliver Hader <oliver.hader@typo3.org>