Remove UniqueId.uniqueIdFormat field

[mpkorstanje]

The UniqueIdFormat is a singleton instance and not part of the public API, as such is effectively constant. Tracking the format in every UniqueId is unnecessary and makes the larger than it needs to be.

In 2016 in 0e5ab97 the UniqueId.uniqueIdFormat was added with the message:

• UniqueId now tracks the UniqueIdFormat it was created with in order to avoid accidentally switching to the default format when appending new segments to an existing UniqueId.

But at the time UniqueIdFormat was public and not a singleton.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[testlens-app]

✅ All tests passed ✅

🏷️ Commit: 94f1cd3
▶️ Tests: 38003 executed
⚪️ Checks: 15/15 completed

[mpkorstanje]

Open questions for team discussion:

• Can we change the serial version of UniqueId?

[marcphilipp]

Can we change the serial version of UniqueId?

We should do so in a minor release. We could work around this by introducing custom writeObject/readObject methods (like we used to have for TestIdentifier in 5.x) that write null and ignore any read value.

[mpkorstanje]

We should do so in a minor release. We could work around this by introducing custom writeObject/readObject methods

Did you mean that as a workaround for the limitation of releasing this in a minor release and as a condition for a patch release, or as a work around for changing the serial version and as a condition for a minor release rather than a major release? Or can this go into the next minor release without custom methods?