GPII-526: Removed screenReaderTTSEnabled transformation from the NVDA

Removed screenReaderTTSEnabled transformation from the NVDAsolution registry as it didn't really make much sense to use there. That common term is rather a flag to the matchmaker to launch/not launch a screenreader. Plus it had the unfortunate side-effect to always launch screenreader, which screenReaderTTSEnabled=false is a request not to have happen