Kotlin: Implement lockless TRAP writing

[igfoo]

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Rather than using lock files and rewriting TRAP file, and storing the metadata in a .metadata file, we now encode the metadata in the filename and rename all but the newest TRAP file so that the importer doesn't see them.

So we might end up with e.g.

    Text.members#0.0-1664381081060-java.trap.gz
    Text.members#55.0-1658481279000-java.trap-old.gz
    Text.members#55.0-1664381081060-java.trap-old.gz

For now, you can go back to the old system by setting

    CODEQL_EXTRACTOR_JAVA_TRAP_LOCKING=true

in the environment.