Today we log a "deleting snapshots [...] from repository [...]" message at INFO level [almost the first thing](https://github.com/elastic/elasticsearch/blob/dfaec0dbf0c8a0ba2912381334019725848f1f5a/server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java#L1886-L1888) when we start the deletion. However, the requested snapshots may not exist or they may be wildcards to be matched against actual snapshots. In these cases, the log message is either misleading or insuffiicent. Instead we should log the message after we have successfully added the delete to the cluster state similar to how the [logging works for snapshot creation](https://github.com/elastic/elasticsearch/blob/f77c16b78bab5e9f3ee24974aeba408e254e8c94/server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java#L3804).
server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java
ShardGeneration generation,
                T shardId
            ) {
                startShardOperation(newStates, shardId, new ShardSnapshotStatus(nodeId, generation));
            }
            /**
             * Start shard level operation for given {@code shardId}.
             *
             * @param newStates builder for updated shard states mapping
             * @param shardId   shard identifier of shard to start operation for
             * @param newState  new shard task state for operation to start
             * @param <T>       either {@link ShardId} for snapshots or {@link RepositoryShardId} for clones
             */
            private <T> void startShardOperation(
                ImmutableOpenMap.Builder<T, ShardSnapshotStatus> newStates,
                T shardId,
                ShardSnapshotStatus newState
            ) {
                logger.trace(
                    "[{}] Starting [{}] on [{}] with generation [{}]",
                    entry.snapshot(),
                    shardId,
                    newState.nodeId(),
                    newState.generation()
                );
                newStates.put(shardId, newState);
                iterator.remove();
                startedCount++;
            }
            private <T> void executeShardSnapshotUpdate(