MINOR: Add Append KRaft Version Record to BatchAccumulator

[nihyxx]

What

This minor PR adds a function to append the KRaft Version Record in BatchAccumulator. This is needed to implement KRaft upgrade (https://issues.apache.org/jira/browse/KAFKA-16538).

Summary of testing strategy (including rationale)
for the feature or bug fix. Unit and/or integration
tests are expected for any behaviour change and
system tests should be considered for larger changes.

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[jsancio]

Thanks for the changes @nihyxx. Just some minor comments.

[jsancio]

We indent by 4 spaces in Java code.

    public void appendKRaftVersionRecord(
        KRaftVersionRecord kraftVersionRecord,
        long currentTimestamp
    ) {

[jsancio]

We indent by 4 spaces in Java code.

        appendControlMessages((baseOffset, epoch, compression, buffer) ->
            MemoryRecords.withKRaftVersionRecord(
                baseOffset,
                currentTimestamp,
                epoch,
                buffer,
                kraftVersionRecord
            )
        );

[jsancio]

We indent by 4 spaces in Java code.

        Mockito.when(memoryPool.tryAllocate(maxBatchSize))
            .thenReturn(buffer);

        BatchAccumulator<String> acc = buildAccumulator(
            leaderEpoch,
            baseOffset,
            lingerMs,
            maxBatchSize
        );