[SFN] Add support for previousEventId

[MEPalma]

Motivation

When dispatching GetExecutionHistory calls about some State Machine Execution, the current implementation would compile previousEventId values according to a global incremental counter. This logic means that in information about the true event source of any event is often incorrect, especially for distributed workflows such as Map and Parallel states. This PR aims at ensuring that for each event, the true source event id is provided.

Changes

Introduces a EventHistoryContext in Environment objects. These allow the interpreter to cache the last event id published. As each context object operates in its own evaluation scope, this is information is ensured to not be tampered by the global execution of the program. Values in the context can then be resynchronised with the parent scope during frame closing operations, or skipped through frame deletion operations (see MapRun workflows).
Evaluation logic for map iteration workers is modified to fit this new design, and resolved a number of concurrency issues when closing pool jobs or evaluation stops.
Related changes extend to other relevant state resolvers such as state_map and state_parallel.

Testing

• removes all skip_snapshot_verify for previous_event_id
• enables test_sfn_scenarios for v2

[github-actions]

LocalStack Community integration with Pro

       2 files         2 suites   1h 7m 26s ⏱️
2 259 tests 1 684 ✔️ 575 💤 0 ❌
2 260 runs  1 684 ✔️ 576 💤 0 ❌

Results for commit bffa43c.

♻️ This comment has been updated with latest results.

[coveralls]

coverage: 82.927% (+0.07%) from 82.861% when pulling bffa43c on MEP-sfn-prev_id into ca43d39 on master.

[dominikschubert]

LGTM, thanks for jumping on this. 🚀

[dominikschubert]

great to see that we can start removing some skipped verifications 🚀