Add version to default remote configuration and don't update unless remote configuration is newer

[matus-tomlein]

When the user configures the tracker using remote configuration and sets a default configuration, the default configuration will always be replaced by the fetched configuration regardless of whether it is different or not. This causes a new session to start (since a new tracker is created).

To prevent replacing the tracker in case the remote configuration is the same as the default configuration, we should add a configuration version to the default configuration and only replace it if the fetched configuration has a higher version.

[davidher-mann]

Thanks for creating the issue. Since the first session (app install session) is super relevant to generate insights, optimize onboarding flows and marketing spend etc. it would be great to tackle the issue in the upcoming weeks.