Switch to ULID

[coderbyheart]

A globally unique ID is needed, and ULID has advantages over UUID v4, so switch over to ULID.

See https://github.com/ulid/spec\#universally-unique-lexicographically-sortable-identifier

Caveats:

• ULID exposes creation timestamp, which is not a problem in this project
• not yet supported in AWS IoT

Task:

• replace usage of v4() with Ulid.generate().toCanonical()
• because ULIDs are sortable, remove the use of a separate timestamp column if only used for sorting (because ULID uses Unix epoch which has no timezone)