* Adds functionality to advertise for a set duration, similar to NimBLEScan::start.
The first parameter being the duration (in seconds).
The second parameter is a pointer to a callback function that is invoked when advertising stops.
* NimBLEAdvertising::isAdvertising method added, returns true if advertising is currently active.
* These methods were noop's and are now removed due to lack of usefulness and advertisment space consumed if used.
Applications can still manually set these values if desired using NimBLEAdvertisementData::addData.
* Get service handles on server start
* remove service + indicate service changed
* Reset gatt services when no connections active and services changed.
* NimBLEServer::createService can now be used any time and will send service changed
indication if server was already active.
* Add ability to remove advertised serviceUUIDS
* Adds addService() method to server to be allow user to re-add a service previously removed
* Add destructior to NimBLEServer, NimBLEService and NimBLECharacteristic to release allocated resources.
* Use critical sections to access characteristic/descriptor value data.
* Remove unnecessary code
* Create characteristic semaphore only if needed for indications.
* Fix advertising when not broadcasting a service.
Previously we used createServer() to get a reference to the server instance.
This was problematic when using advertising only as it would create a server
when starting advertising. This prevents that and provides better semantics.
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.
