Add support for writing V2 Checkpoints

Adds capability to write V2 Checkpoints. This PR only adds write support. More Unit Tests to follow in an upcoming PR which will add read support.

Closes #2031

GitOrigin-RevId: c3a889b8f67829ec48f6ff650d4d77b75531288f

spark/src/main/scala/org/apache/spark/sql/delta/CheckpointProvider.scala

@@ -16,6 +16,7 @@
 
 package org.apache.spark.sql.delta
 
+import org.apache.spark.sql.delta.actions.Protocol
 import org.apache.spark.sql.delta.metering.DeltaLogging
 import org.apache.spark.sql.delta.sources.DeltaSQLConf
 import org.apache.spark.sql.delta.util.FileNames._
@@ -59,6 +60,19 @@ trait CheckpointProvider extends UninitializedCheckpointProvider {
   def allActionsFileIndexes(): Seq[DeltaLogFileIndex]
 }
 
+object CheckpointProvider extends DeltaLogging {
+
+  private[delta] def isV2CheckpointEnabled(protocol: Protocol): Boolean =
+    protocol.isFeatureSupported(V2CheckpointTableFeature)
+
+  /**
+   * Returns whether V2 Checkpoints are enabled or not.
+   * This means an underlying checkpoint in this table could be a V2Checkpoint with sidecar files.
+   */
+  def isV2CheckpointEnabled(snapshotDescriptor: SnapshotDescriptor): Boolean =
+    isV2CheckpointEnabled(snapshotDescriptor.protocol)
+}
+
 /**
  * An implementation of [[CheckpointProvider]] where the information about checkpoint files
  * (i.e. Seq[FileStatus]) is already known in advance.