[DRAFT] feat(datastore): Add ConnectivityMonitor to RemoteSyncEngine

[lawmicha]

Issue #

Description

This PR starts will pulling in the ConnectivityMonitor, see aws-amplify/aws-appsync-realtime-client-ios#58 for a reference implementation. The code copied over is owned by the DataStore plugin and used internally by the RemoteSyncEngine. There is also another NetworkMonitor usage in analytics here https://github.com/aws-amplify/amplify-swift/blob/main/AmplifyPlugins/Analytics/Sources/AWSPinpointAnalyticsPlugin/Support/Utils/NetworkMonitor.swift for reference.

The initial commit only adds the classes and instantiates a connectivity monitor, and does not build much logic around it.

General Checklist

• Added new tests to cover change, if needed
• Build succeeds with all target using Swift Package Manager
• All unit tests pass
• All integration tests pass
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• New or updated tests include Given When Then inline code documentation and are named accordingly testThing_condition_expectation()
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.