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
final SnapshotId snapshotId = new SnapshotId(snapshotName, UUIDs.randomBase64UUID()); 
        Repository repository = repositoriesService.repository(request.repository());
        if (repository.isReadOnly()) {
            listener.onFailure(new RepositoryException(repository.getMetadata().name(), "cannot create snapshot in a readonly repository"));
            return;
        }
        submitCreateSnapshotRequest(request, listener, repository, new Snapshot(repositoryName, snapshotId), repository.getMetadata());
    }
    private void submitCreateSnapshotRequest(
        CreateSnapshotRequest request,
        ActionListener<Snapshot> listener,
        Repository repository,
        Snapshot snapshot,
        RepositoryMetadata initialRepositoryMetadata
    ) {
        repository.getRepositoryData(
            listener.delegateFailure(
                (l, repositoryData) -> masterServiceTaskQueue.submitTask(
                    "create_snapshot [" + snapshot.getSnapshotId().getName() + ']',
                    new CreateSnapshotTask(repository, repositoryData, l, snapshot, request, initialRepositoryMetadata),
                    request.masterNodeTimeout()
                )
            )
        );
    }
    private static void ensureSnapshotNameNotRunning(SnapshotsInProgress runningSnapshots, String repositoryName, String snapshotName) {
        if (runningSnapshots.forRepo(repositoryName).stream().anyMatch(s -> s.snapshot().getSnapshotId().getName().equals(snapshotName))) {
            throw new SnapshotNameAlreadyInUseException(repositoryName, snapshotName, "snapshot with the same name is already in-progress");
        }
    }