Ember dongle driver refactoring for multinetwork

[cdjackson]

I plan to refactor the Ember dongle driver to split out functions that are specific to the NCP, and to a network. This is to allow support for multiple networks within a single dongle.

This is expected to look something along the following lines -:

The current ZigBeeDongleEzsp class will continue to work as it currently does, but this will be a simple class that calls functions in the EmberNcpHandler and EmberNetworkHandler classes.

This is currently implemented, although I'm still trying to work out how to get the multi network NCP working (Silabs docs are non existent in this area for EZSP - they all assume you use their framework).

@hsudbrock @triller-telekom FYI

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.