* Replace all semaphores with task notifications.
* use critical sections to prevent concurrent data access.
* Ensure scan stop has been called before connecting.
* Optimize and cleanup
* Add template casting to NimBLERemoteDescriptor::readValue()
* Removed storage of the descriptor value read as it did not serve any purpose.
This allows NimBLE options in menuconfig to reduce code size based on
the roles selected (scan/advertising/central/peripheral).
Significant code space can be saved by removing unnecessary roles for the application.
