Introduce LettuceInvoker.

We now use LettuceInvoker to call Lettuce API methods for synchronous, pipelining, and transactional execution models. LettuceInvoker captures the method invocation as functional utility and allows conversion of results:

Long result = invoker.just(RedisGeoAsyncCommands::geoadd, key, point.getX(), point.getY(), member);

List<byte[]> result = invoker.fromMany(RedisGeoAsyncCommands::geohash, key, members)
 				.toList(it -> it.getValueOrElse(null));

Closes #1797
Original Pull Request #1948

Author: mp911de

src/main/java/org/springframework/data/redis/connection/RedisListCommands.java

@@ -75,6 +75,7 @@ default Long lPos(byte[] key, byte[] element) {
 	 * @see <a href="https://redis.io/commands/lpos">Redis Documentation: LPOS</a>
 	 * @since 2.4
 	 */
+	@Nullable
 	List<Long> lPos(byte[] key, byte[] element, @Nullable Integer rank, @Nullable Integer count);
 
 	/**

src/main/java/org/springframework/data/redis/connection/lettuce/LettuceClusterHyperLogLogCommands.java

@@ -38,14 +38,9 @@ class LettuceClusterHyperLogLogCommands extends LettuceHyperLogLogCommands {
 	public Long pfCount(byte[]... keys) {
 
 		if (ClusterSlotHashUtil.isSameSlotForAllKeys(keys)) {
-
-			try {
-				return super.pfCount(keys);
-			} catch (Exception ex) {
-				throw convertLettuceAccessException(ex);
-			}
-
+			return super.pfCount(keys);
 		}
+
 		throw new InvalidDataAccessApiUsageException("All keys must map to same slot for pfcount in cluster mode.");
 	}
 
@@ -59,14 +54,10 @@ public void pfMerge(byte[] destinationKey, byte[]... sourceKeys) {
 		byte[][] allKeys = ByteUtils.mergeArrays(destinationKey, sourceKeys);
 
 		if (ClusterSlotHashUtil.isSameSlotForAllKeys(allKeys)) {
-			try {
-				super.pfMerge(destinationKey, sourceKeys);
-				return;
-			} catch (Exception ex) {
-				throw convertLettuceAccessException(ex);
-			}
-
+			super.pfMerge(destinationKey, sourceKeys);
+			return;
 		}
+
 		throw new InvalidDataAccessApiUsageException("All keys must map to same slot for pfmerge in cluster mode.");
 	}
 }