[featue] move events module to sbtc crate

[MCJOHN974]

Description

Closes #1016

Changes

Testing Information

Checklist:

• I have performed a self-review of my code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[MCJOHN974]

Yeah, I also don't like creating 3rd PR for same issue but I guess this commit considers all previous notes and is good enough now

[MCJOHN974]

@djordon I believe few commits above fixes all review notes except "We should use local types for key rotation events ". For this note I'm wondering if we want to have any difference between local and sbtc key rotation events. If yes than how this differences should look like.

[djordon]

I realized that we'll also want to move the signer/src/stacks/webhooks.rs file over to the sbtc crate as well. You'll should feature gate the webhooks module though and if you like I can help with that.

[MCJOHN974]

I realized that we'll also want to move the signer/src/stacks/webhooks.rs file over to the sbtc crate as well. You'll should feature gate the webhooks module though and if you like I can help with that.

Maybe this pr is in progress for too long and refactoring webhooks and events are different enough tasks to make them in separate pr

[MCJOHN974]

@djordon I think commits above fix new issues and we can go back to question "how local KeyRotationEvent should look like?", if we still want to have another local type

upd: I think local KeyRotationEvent I suggested in next commit quite fits to style we used to create local types for other events

[djordon]

Looks good ✅