### 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/main/java/org/elasticsearch/index/mapper/DocumentParser.java
}
        @Override
        public String typeName() {
            throw new UnsupportedOperationException();
        }
        @Override
        public MappedFieldType fieldType() {
            throw new UnsupportedOperationException();
        }
        @Override
        public MultiFields multiFields() {
            throw new UnsupportedOperationException();
        }
        @Override
        public Iterator<Mapper> iterator() {
            throw new UnsupportedOperationException();
        }
        @Override
        protected void doValidate(MappingLookup mappers) {
            throw new UnsupportedOperationException();
        }
        @Override
        protected void checkIncomingMergeType(FieldMapper mergeWith) {
            throw new UnsupportedOperationException();
        }
        @Override
        public Builder getMergeBuilder() {
            throw new UnsupportedOperationException();
        }
        @Override