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
ClusterState state,
            ActionListener<ActionResponse.Empty> listener
        ) {
            innerUpdateSnapshotState(
                request.snapshot(),
                request.shardId(),
                null,
                request.status(),
                listener.map(v -> ActionResponse.Empty.INSTANCE)
            );
        }
        @Override
        protected ClusterBlockException checkBlock(UpdateIndexShardSnapshotStatusRequest request, ClusterState state) {
            return null;
        }
    }
    /**
     * Cluster state update task that removes all {@link SnapshotsInProgress.Entry} and {@link SnapshotDeletionsInProgress.Entry} for a
     * given repository from the cluster state and afterwards fails all relevant listeners in {@link #snapshotCompletionListeners} and
     * {@link #snapshotDeletionListeners}.
     */
    private final class FailPendingRepoTasksTask extends ClusterStateUpdateTask {
        
        private final List<Snapshot> snapshotsToFail = new ArrayList<>();
        
        private final List<String> deletionsToFail = new ArrayList<>();
        
        private final Exception failure;
        private final String repository;
        FailPendingRepoTasksTask(String repository, Exception failure) {