feat: add deep-array value-equality helpers in sdk-core

[OmarAlJarrah]

Summary

Adds ValueEquality to org.dexpace.sdk.core.util — content-deep contentEquals / contentHashCode helpers for value types that hold array-typed fields.

java.util.Objects.equals/hashCode compare arrays by identity, so two structurally-equal ByteArray fields (or any array-typed field) are reported unequal and hash differently. A value type with array fields therefore cannot rely on Objects.equals for a correct equals/hashCode. These helpers compare by content instead.

Behavior

• contentEquals(a, b) / contentHashCode(value), both @JvmStatic and null-safe (two nulls equal; null hashes to 0).
• Primitive arrays (ByteArray, IntArray, DoubleArray, …) compared by element value.
• Object arrays compared with Arrays.deepEquals / deepHashCode, so nested and arbitrarily-deep multi-dimensional arrays compare structurally, and object-array elements use their own equals.
• Distinct array kinds (object vs primitive, IntArray vs LongArray) are not equal even with matching values, mirroring the JVM's distinct array types.
• Non-array values fall back to ordinary equals/hashCode.
• The two methods are mutually consistent: whenever contentEquals(a, b) is true, contentHashCode(a) == contentHashCode(b).

No core type needs it today; it is the hand-usable runtime primitive a DTO generator (or a hand-written value type) targets for array fields. No code generation is introduced.

Tests

ValueEqualityTest covers nulls, identity shortcut, scalars, every primitive-array kind, object arrays (including null elements), nested object arrays, nested primitive arrays, deeply-nested multi-dimensional arrays, custom value-type elements, cross-kind mismatches, and equals/hashCode consistency.

Gated build (module-scoped)

./gradlew :sdk-core:test :sdk-core:ktlintCheck :sdk-core:detekt :sdk-core:apiDump --no-daemon
./gradlew :sdk-core:apiCheck --no-daemon

Both BUILD SUCCESSFUL. The regenerated sdk-core/api/sdk-core.api snapshot is committed.

Closes #49

[OmarAlJarrah]

Adds a ValueEquality utility in sdk-core with contentEquals and contentHashCode static helpers that give deep, structural comparison for value types holding arrays, dispatching object arrays through Arrays.deepEquals/deepHashCode, each primitive-array kind through Kotlin's content helpers, and falling back to plain equals/hashCode otherwise. Looks good to merge.

The dispatch covers all eight primitive-array types plus object arrays, with equals/hashCode as the fallback, and the two helpers stay consistent with each other so equal values hash equally. The @JvmStatic surface is Java-friendly and the regenerated sdk-core.api snapshot matches the new public API. Test coverage is thorough: nulls, identity, scalars, every primitive-array kind, object arrays with null elements, nested/multi-dimensional arrays, custom element types, and cross-kind mismatches.