fix: remove a data race when auto-generated device id is used instead of custom device id

[falconandy]

Summary

1. Adds a new configuration option deviceId to prevent device id auto-generation.
2. Adds a new internal setDeviceId() method that sets device id if current and expected device ids are equal.
3. Switches amplitudeDispatcher to single thread mode
4. Adds tests that reproduce the fixed data race.

Checklist

• [x] Does your PR title have the correct title format?
• Does your PR have a breaking change?: No

[justin-fiedler]

Resolved in #177