fix(otel): set invocation span metadata

[zhongkechen]

Summary

• explicitly mark every span created by the OTel plugin as SpanKind.INTERNAL
• add durable.invocation.first as a boolean when each invocation span starts
• add durable.invocation.status as a string when each invocation span ends
• keep invocation span status UNSET while an execution is pending or retrying
• mark the terminal invocation span OK for successful executions and ERROR for failed executions
• add regression coverage for span kinds, both first-invocation values, and every invocation status

issue: aws/aws-durable-execution-conformance-tests#23

Verification

• hatch run dev-otel:test (60 passed)
• hatch run dev-otel:typecheck
• hatch fmt --check from the OTel package
• hatch run python .github/scripts/lintcommit.py