### Description

We now support storing KNN vectors as part of our indexed data.  These vectors should be included in the disk usage API.
server/src/main/java/org/elasticsearch/action/admin/indices/diskusage/IndexDiskUsageAnalyzer.java
private final Map<Integer, Long> fields = new HashMap<>();
        private void trackField(FieldInfo fieldInfo, int fieldLength) {
            final int totalBytes = fieldLength + Long.BYTES; 
            fields.compute(fieldInfo.number, (k, v) -> v == null ? totalBytes : v + totalBytes);
        }
        @Override
        public void binaryField(FieldInfo fieldInfo, byte[] value) throws IOException {
            trackField(fieldInfo, Integer.BYTES + value.length);
        }
        @Override
        public void stringField(FieldInfo fieldInfo, String value) throws IOException {
            trackField(fieldInfo, Integer.BYTES + value.getBytes(StandardCharsets.UTF_8).length);
        }
        @Override