Kotlin coroutine update. (#1135)

As the Flow interface is not stable for inheritance in 3rd party libraries,
use delegation instead.

JAVA-4950

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/AggregateFlow.kt

@@ -34,7 +34,7 @@ import org.bson.conversions.Bson
  * @param T The type of the result.
  * @see [Aggregation command](https://www.mongodb.com/docs/manual/reference/command/aggregate)
  */
-public class AggregateFlow<T : Any>(private val wrapped: AggregatePublisher<T>) : Flow<T> {
+public class AggregateFlow<T : Any>(private val wrapped: AggregatePublisher<T>) : Flow<T> by wrapped.asFlow() {
 
     /**
      * Sets the number of documents to return per batch.

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/DistinctFlow.kt

@@ -30,7 +30,7 @@ import org.bson.conversions.Bson
  * @param T The type of the result.
  * @see [Distinct command](https://www.mongodb.com/docs/manual/reference/command/distinct/)
  */
-public class DistinctFlow<T : Any>(private val wrapped: DistinctPublisher<T>) : Flow<T> {
+public class DistinctFlow<T : Any>(private val wrapped: DistinctPublisher<T>) : Flow<T> by wrapped.asFlow() {
 
     /**
      * Sets the number of documents to return per batch.

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/FindFlow.kt

@@ -34,7 +34,7 @@ import org.bson.conversions.Bson
  * @param T The type of the result.
  * @see [Collection filter](https://www.mongodb.com/docs/manual/reference/method/db.collection.find/)
  */
-public class FindFlow<T : Any>(private val wrapped: FindPublisher<T>) : Flow<T> {
+public class FindFlow<T : Any>(private val wrapped: FindPublisher<T>) : Flow<T> by wrapped.asFlow() {
 
     /**
      * Sets the number of documents to return per batch.

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/ListCollectionsFlow.kt

@@ -29,7 +29,8 @@ import org.bson.conversions.Bson
  * @param T The type of the result.
  * @see [List collections](https://www.mongodb.com/docs/manual/reference/command/listCollections/)
  */
-public class ListCollectionsFlow<T : Any>(private val wrapped: ListCollectionsPublisher<T>) : Flow<T> {
+public class ListCollectionsFlow<T : Any>(private val wrapped: ListCollectionsPublisher<T>) :
+    Flow<T> by wrapped.asFlow() {
     /**
      * Sets the maximum execution time on the server for this operation.
      *

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/ListDatabasesFlow.kt

@@ -29,7 +29,7 @@ import org.bson.conversions.Bson
  * @param T The type of the result.
  * @see [List databases](https://www.mongodb.com/docs/manual/reference/command/listDatabases/)
  */
-public class ListDatabasesFlow<T : Any>(private val wrapped: ListDatabasesPublisher<T>) : Flow<T> {
+public class ListDatabasesFlow<T : Any>(private val wrapped: ListDatabasesPublisher<T>) : Flow<T> by wrapped.asFlow() {
     /**
      * Sets the maximum execution time on the server for this operation.
      *

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/ListIndexesFlow.kt

@@ -28,7 +28,7 @@ import org.bson.BsonValue
  * @param T The type of the result.
  * @see [List indexes](https://www.mongodb.com/docs/manual/reference/command/listIndexes/)
  */
-public class ListIndexesFlow<T : Any>(private val wrapped: ListIndexesPublisher<T>) : Flow<T> {
+public class ListIndexesFlow<T : Any>(private val wrapped: ListIndexesPublisher<T>) : Flow<T> by wrapped.asFlow() {
     /**
      * Sets the maximum execution time on the server for this operation.
      *

driver-kotlin-coroutine/src/main/kotlin/com/mongodb/kotlin/client/coroutine/MapReduceFlow.kt

@@ -36,7 +36,7 @@ import org.bson.conversions.Bson
  * @see [Map Reduce](https://www.mongodb.com/docs/manual/reference/command/mapReduce/)
  */
 @Deprecated("Map Reduce has been deprecated. Use Aggregation instead", replaceWith = ReplaceWith(""))
-public class MapReduceFlow<T : Any>(private val wrapped: MapReducePublisher<T>) : Flow<T> {
+public class MapReduceFlow<T : Any>(private val wrapped: MapReducePublisher<T>) : Flow<T> by wrapped.asFlow() {
     /**
      * Sets the number of documents to return per batch.
      *