Actions `cluster:admin/repository/analyze/blob` and `cluster:admin/repository/analyze/register` and so on are only invoked via the transport service, they do not need to register as client actions so we can drop the `ActionType` instance. Instead the root `RepositoryAnalyzeAction` should create and register all these transport actions itself. But even the root `RepositoryAnalyzeAction` should not be an `ActionType` derivative, we should just declare an `ActionType` instance directly. Moreover we can use `ActionType#localOnly` since the client action does not run on remote clusters.
x-pack/plugin/snapshot-repo-test-kit/src/main/java/org/elasticsearch/repositories/blobstore/testkit/BlobAnalyzeAction.java
@Override
        public void writeTo(StreamOutput out) throws IOException {
            out.writeString(nodeId);
            out.writeString(nodeName);
            out.writeString(blobName);
            out.writeVLong(blobLength);
            out.writeBoolean(readEarly);
            out.writeBoolean(overwrite);
            out.writeVLong(checksumStart);
            out.writeVLong(checksumEnd);
            out.writeVLong(writeElapsedNanos);
            out.writeVLong(overwriteElapsedNanos);
            out.writeVLong(writeThrottledNanos);
            out.writeCollection(readDetails);
        }
        @Override
        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
            builder.startObject();
            builder.startObject("blob");
            builder.field("name", blobName);
            builder.humanReadableField("size_bytes", "size", ByteSizeValue.ofBytes(blobLength));
            builder.field("read_start", checksumStart);
            builder.field("read_end", checksumEnd);
            builder.field("read_early", readEarly);
            builder.field("overwritten", overwrite);
            builder.endObject();
            builder.startObject("writer_node");
            builder.field("id", nodeId);
            builder.field("name", nodeName);
            builder.endObject();