Add transaction interruption support for internal use

This update is for Neo4j internal use only.

Author: injectives

driver/src/main/java/org/neo4j/driver/internal/async/UnmanagedTransaction.java

@@ -91,6 +91,7 @@ private enum State {
     private CompletableFuture<Void> commitFuture;
     private CompletableFuture<Void> rollbackFuture;
     private Throwable causeOfTermination;
+    private CompletionStage<Void> interruptStage;
 
     public UnmanagedTransaction(Connection connection, BookmarksHolder bookmarksHolder, long fetchSize) {
         this(connection, bookmarksHolder, fetchSize, new ResultCursorsHolder());
@@ -303,4 +304,21 @@ private CompletionStage<Void> closeAsync(boolean commit, boolean completeWithNul
 
         return stage;
     }
+
+    /**
+     * Marks transaction as terminated and sends {@code RESET} message over allocated connection.
+     * <p>
+     * <b>THIS METHOD IS NOT PART OF PUBLIC API</b>
+     *
+     * @return {@code RESET} response stage
+     */
+    public CompletionStage<Void> interruptAsync() {
+        return executeWithLock(lock, () -> {
+            if (interruptStage == null) {
+                markTerminated(null);
+                interruptStage = connection.reset();
+            }
+            return interruptStage;
+        });
+    }
 }

driver/src/main/java/org/neo4j/driver/internal/reactive/InternalReactiveTransaction.java

@@ -57,4 +57,15 @@ public Publisher<ReactiveResult> run(Query query) {
                 })
                 .map(InternalReactiveResult::new);
     }
+
+    /**
+     * Marks transaction as terminated and sends {@code RESET} message over allocated connection.
+     * <p>
+     * <b>THIS METHOD IS NOT PART OF PUBLIC API</b>
+     *
+     * @return {@code RESET} response publisher
+     */
+    public Publisher<Void> interrupt() {
+        return Mono.fromCompletionStage(tx.interruptAsync());
+    }
 }