[kernel-spark] Implement MetadataEvolutionHandler in v2 (#6563)

## 🥞 Stacked PR
Use this [link](https://github.com/delta-io/delta/pull/6563/files) to
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[stack/SparkMetadataAdapter](#6546)
[[Files changed](https://github.com/delta-io/delta/pull/6546/files)]
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[stack/RefactorMetadataTrackingLog](#6550)
[[Files changed](https://github.com/delta-io/delta/pull/6550/files)]
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[stack/RefactorDeltaSourceMetadataEvolutionSupport](#6562)
[[Files changed](https://github.com/delta-io/delta/pull/6562/files)]
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[**stack/MetadataEvolutionHandler2**](#6563)
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[stack/NonAdditiveSchemaEvolution2](#6570)
[[Files
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[stack/NonAdditiveSchemaEvolution3](#6697)
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[stack/consecutiveSchemaChangesMerger](#6698)
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- [stack/V1V2MixTest](#6759)
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#### Which Delta project/connector is this regarding?

- [X] Spark
- [ ] Standalone
- [ ] Flink
- [ ] Kernel
- [ ] Other (fill in here)

## Description

PR 4/7 in the non-additive schema evolution for V2 streaming connector
stack.

Introduce `MetadataEvolutionHandler`, a Java class that implements the
V1 barrier protocol for schema evolution in the V2 connector. In V1 this
logic lives in `DeltaSourceMetadataEvolutionSupport`, a Scala trait
mixed into `DeltaSource` that accesses stream state via `this`. Since
V2's `SparkMicroBatchStream` is Java and cannot use Scala trait mixins,
`MetadataEvolutionHandler` receives all dependencies via constructor
injection instead.

The handler covers the full schema evolution lifecycle:
- **Stream start**: eager metadata tracking log initialization on first
batch
- **Offset generation**: injects `METADATA_CHANGE_INDEX` /
`POST_METADATA_CHANGE_INDEX` barrier sentinels into the file change
iterator
- **Pending schema offsets**: returns barrier offsets for in-progress
schema changes
- **Batch commit**: updates the schema log and throws
`DELTA_STREAMING_METADATA_EVOLUTION` to trigger stream restart
- **Batch planning on restart**: validates and re-initializes the schema
log

All detection logic delegates to the shared
`DeltaSourceMetadataEvolutionSupport$` companion object statics
(refactored in PR 3/7). V2-specific orchestration is limited to wiring
the barrier protocol into the `CloseableIterator<IndexedFile>` pipeline
and collecting metadata/protocol from Kernel commit ranges via
`StreamingHelper`.

Also extends `StreamingHelper` with
`getMetadataAndProtocolForVersionRange` to collect metadata and protocol
actions from a range of Kernel commits.

## How was this patch tested?

Unit tests in `MetadataEvolutionHandlerTest.java` covering: barrier
protocol (METADATA_CHANGE_INDEX / POST_METADATA_CHANGE_INDEX offset
generation), tracking state transitions, initialization lifecycle,
offset arithmetic, pending schema change handling, and commit-time
evolution exception.

## Does this PR introduce _any_ user-facing changes?

No.

Author: PorridgeSwim