Initital Tweak to using a State Machine

[derekpierre]

• Transition to the use of a formalized state machine
  • Separate state of machine from tracking of transactions
  • Minor renames (more personal preference than functional)
• Don't default to stdout logging (this affects users of the library eg. nucypher) - but use it for tests/examples.
  • Use single logger from twisted - can be changed if needed in logging module.
• Moved blockchain general functionality to utils - get_receipt, get_confirmations etc.
• Memoize average blocktime since unnecessary to recalculate every time
• Use typehints for hook callable, except for on_fault which I think may need to be split into 2 separate scenarios without common parameters:
  • a) rpc issue i.e. tx never broadcasted
  • b) tx broadcasted and there was a problem

I believe this is a first step - the functionality is now on par with what was present before move to using a state machine. Running the retrytx example works. Still more work to do in hooks, pause and how to resume, idling vs sleeping (and concurrency), on_fault hook clarification - added TODOs for follow-up PRs.

I'm light on tests because I would like buy-in to the state machine strategy before it becomes more entrenched. I think understanding the transitions, and what actions are taken based on current/transitioning state makes the system more understandable - of course others may disagree.

Related to https://github.com/nucypher/nucypher/issues/3453

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 90.35533% with 19 lines in your changes are missing coverage. Please review.

:exclamation: No coverage uploaded for pull request base (main@fada083). Click here to learn what that means.

Files	Patch %	Lines
atxm/machine.py	86.07%	11 Missing :warning:
atxm/utils.py	81.25%	6 Missing :warning:
atxm/main.py	83.33%	1 Missing :warning:
atxm/strategies.py	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8 +/- ## ======================================= Coverage ? 80.30% ======================================= Files ? 13 Lines ? 909 Branches ? 0 ======================================= Hits ? 730 Misses ? 179 Partials ? 0 ```

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