fix: emulator API fixes

fix: errors are raised when emulator lost/found event is raised

Whenever androidEmulatorDiscovery raises `emulatorImageFound` or `emulatorImageLost` event, an error is raised in the code as `devicesService` expects to receive an array, but it receives a single image instead.
Fix the code in devicesService to handle correctly the event. Also add logic to handle the same events from iOSSimulatorDiscovery.

fix: Android emulator images are not correct
In case the Android Emulator image does not have displayName set in the config.ini file, the displayName that CLI sets fallbacks to `hw.device.name` property.
However, this name is not the one that is visible in other tools, like Android Studio for example. As a user I expect to see the same name as in Android Studio.
In order to fix this, fallback to the AvdId value from config.ini file and if it is missing, fallback to `hw.device.name`.

Author: rosen-vladimirov