Convert StageId and TaskId to a record

[wendigo]

QueryId was already converted

Description

Additional context and related issues

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## Section
* Fix some things. ({issue}`issuenumber`)

[wendigo]

Important because of https://github.com/openjdk/jdk/blob/dfd383224dbc2e41c9f44b1acd09ffb179cc38f3/src/hotspot/share/ci/ciField.cpp#L237

Also less lines :)

[martint]

This now exposes a bunch of private fields, so it should not be a record.

[wendigo]

Except for fullId all of these fields were accessed through the corresponding getters:

    public StageId getStageId()
    {
        return stageId;
    }

    public int getPartitionId()
    {
        return partitionId;
    }

    public int getAttemptId()
    {
        return attemptId;
    }

I don't see how accessing fullId() which you can anyway get through toString() breaks encapsulation. All of these fields were accessible externally through the previously exposed API

[martint]

It does break encapsulation because it allows TaskId to be constructed with stageId/partitionId/attemptId that don't agree with fullId

[wendigo]

#26799