Add protocol and configuration bindings for outbound SNS.

[TreyE]

This adds protocol and configuration bindings for outbound SNS messaging using AWS, particularly for SMS messages.

Testing is still pending, as a working application generating events is needed to verify the implementation.

https://app.clickup.com/t/868d7e750

[raghuramg]

I've added a few comments—could you please review them?

In addition to the new protocol implementation, we also improved error messaging, introduced a base channel proxy, and cleaned up the existing operations. I'm happy with these changes.

[TreyE]

I've added a few comments—could you please review them?

In addition to the new protocol implementation, we also improved error messaging, introduced a base channel proxy, and cleaned up the existing operations. I'm happy with these changes.

Absolutely, basic gist of the comments (which I agree with whole heartedly) is the areas in which you have questions I don't provide sufficient documentation or explain what/why I'm doing what is happening in the code. I will do so before I re-submit.

[raghuramg]

Looks good to me

[polographer]

My only comment is that I didn't see a re-connection explicitly in the code. I guess that is to keep the current behaviour of the gem; however, for some reason, I think this new kind of connection is more prone to disconnections. But overall, great work