[ESQL] Implement missing methods of TimeSeriesAggregate (#130218)

The base methods `expressionsResolved()`, `hashCode()` and `equals()` weren't checking `timeBucket`

Author: ivancea

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/logical/TimeSeriesAggregate.java

@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * An extension of {@link Aggregate} to perform time-series aggregation per time-series, such as rate or _over_time.
@@ -74,8 +75,35 @@ public TimeSeriesAggregate with(LogicalPlan child, List<Expression> newGroupings
         return new TimeSeriesAggregate(source(), child, newGroupings, newAggregates, timeBucket);
     }
 
+    @Override
+    public boolean expressionsResolved() {
+        return super.expressionsResolved() && (timeBucket == null || timeBucket.resolved());
+    }
+
     @Nullable
     public Bucket timeBucket() {
         return timeBucket;
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(groupings, aggregates, child(), timeBucket);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+
+        TimeSeriesAggregate other = (TimeSeriesAggregate) obj;
+        return Objects.equals(groupings, other.groupings)
+            && Objects.equals(aggregates, other.aggregates)
+            && Objects.equals(child(), other.child())
+            && Objects.equals(timeBucket, other.timeBucket);
+    }
 }