[!!!][TASK] Remove obsolete "security.enable" Setting
This change removes the `TYPO3.Flow.security.enable` and all mentions
and usages of it.
This setting was initially intended for performance reasons (For
applications without security features) and in order to disable
security for (functional) tests.
For the latter we use a different approach since a while and the
performance hit of security features is also neglect-able since
Flow pre-compiles classes (at least if there is no complex policy
Besides the flag was never evaluated consistently.