### Description

Dynamic mappings can greatly help the getting started experience but they currently don't apply to all types, one example is `dense_vector`.

It's been suggested to automatically map float arrays as dense vectors when there are more than 100 values, or a heuristic along these lines.
server/src/internalClusterTest/java/org/elasticsearch/index/mapper/DynamicMappingIT.java
assertSearchHits(searchResponse, "1", "2", "4");
        searchResponse = client().prepareSearch("test")
            .setQuery(new GeoBoundingBoxQueryBuilder("address.location").setCorners(new GeoPoint(42, -72), new GeoPoint(40, -74)))
            .get();
        assertSearchHits(searchResponse, "3");
    }
    public void testBulkRequestWithNotFoundDynamicTemplate() throws Exception {
        assertAcked(indicesAdmin().prepareCreate("test"));
        final XContentBuilder mappings = XContentFactory.jsonBuilder();
        mappings.startObject();
        {
            mappings.startArray("dynamic_templates");
            {
                if (randomBoolean()) {
                    mappings.startObject();
                    mappings.startObject("location");
                    {
                        if (randomBoolean()) {
                            mappings.field("match", "location");
                        }
                        if (randomBoolean()) {
                            mappings.field("match_mapping_type", "string");
                        }
                        mappings.startObject("mapping");
                        {
                            mappings.field("type", "geo_point");
                        }
                        mappings.endObject();
                    }
                    mappings.endObject();