### Description

It would be really great if [CircleProcessor.java](https://github.com/elastic/elasticsearch/blob/0699c9351f1439e246d408fd6538deafde4087b6/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/ingest/CircleProcessor.java) could be published in some maven artifact.
We are thinking to convert Geoshape Circle into Geoshape Polygon on application side instead of ElasticSearch Server side. The benefits of it is that it would make possible for us to choose `error_distance` dynamically depending on different conditions.
With direct code access to [CircleProcessor.java](https://github.com/elastic/elasticsearch/blob/0699c9351f1439e246d408fd6538deafde4087b6/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/ingest/CircleProcessor.java) and [SpatialUtils.java](https://github.com/elastic/elasticsearch/blob/0699c9351f1439e246d408fd6538deafde4087b6/x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/SpatialUtils.java) it would be possible to make application side custom conversion logic.
ElasticSearch version: >= 8
x-pack/plugin/spatial/src/test/java/org/elasticsearch/xpack/spatial/ingest/CircleProcessorTests.java
for (Object value : new Object[] { null, "not_circle" }) {
            field.put("coordinates", value);
            IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> processor.execute(ingestDocument));
            assertThat(e.getMessage(), equalTo("invalid circle definition"));
        }
    }
    public void testInvalidRadius() {
        Map<String, Object> field = new HashMap<>();
        field.put("type", "circle");
        field.put("coordinates", List.of(100.0, 1.0));
        Map<String, Object> map = new HashMap<>();
        map.put("field", field);
        IngestDocument ingestDocument = TestIngestDocument.withDefaultVersion(map);
        CircleProcessor processor = new CircleProcessor("tag", null, "field", "field", false, 10, GEO_SHAPE);
        for (Object value : new Object[] { null, "NotNumber", "10.0fs" }) {
            field.put("radius", value);
            IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> processor.execute(ingestDocument));
            assertThat(e.getMessage(), equalTo("invalid circle definition"));
        }
    }
    public void testGeoShapeQueryAcrossDateline() throws IOException {
        String fieldName = "circle";
        Circle circle = new Circle(179.999746, 67.1726, randomDoubleBetween(1000, 300000, true));
        int numSides = randomIntBetween(4, 1000);
        Geometry geometry = SpatialUtils.createRegularGeoShapePolygon(circle, numSides);
        GeoShapeWithDocValuesFieldType shapeType = new GeoShapeWithDocValuesFieldType(
            fieldName,
            true,
            false,
            Orientation.RIGHT,