Merge branch 'hotfix/#6398-forward-controller-plugin-fluent-interface-consistency'

Close #6398
Fix documentation
#6895 - `Zend\Log\Processor\Backtrace#getBacktrace()` returns an `array` of `array`s
Merge branch 'hotfix/#6895-correct-log-processor-get-backtrace-return-type' into develop

Close #6895
Forward port #6895