Add app registration handling and update version to 0.2.2

[mad201802]

This pull request introduces improvements to the service discovery mechanism and subscription handling in the Sero project, along with version updates and a new regression test. The main focus is on ensuring subscriptions are correctly reactivated after provider reconnections, even if retries were previously exhausted, and clarifying the distinction between app-registered and active subscriptions.

Service Discovery and Subscription Improvements:

• Added app_registered flag to the SubTracker struct in ServiceDiscovery, ensuring subscriptions are only reactivated on provider reconnect if the app still wants them. This clarifies the difference between subscriptions requested by the app and those merely active.
• Updated subscription logic to set app_registered to true when subscribing and false when unsubscribing, preventing unwanted reactivation of subscriptions after reconnects. [1] [2]
• Modified resubscription logic to only flag app-registered subscriptions (not just active ones) for re-send on provider reboot, and to revive trackers whose retries were exhausted.

Testing Enhancements:

• Added a regression test to ensure subscriptions are reactivated and SD_SUBSCRIBE_EVENT is sent after provider reconnect, even if ACK retries were previously exhausted.

Version Updates:

• Bumped project version in CMakeLists.txt and Node module package.json from 0.2.1 to 0.2.2. [1] [2]

Network Configuration:

• Changed the UDP transport initialization address in examples/server.cpp from 127.0.0.1 to 192.168.1.132.