Add Zstd to N5CompressorFactory.scala (#8703)

N5 supports Zstandard compression via
https://github.com/JaneliaSciComp/n5-zstandard

### Steps to test:
- Test against
https://s3.janelia.org/keller-lab/s12a/samples_for_stitching/fly_brain_3/basic_corrected/dataset.n5/setup201/timepoint0/s4/
with the following attributes.json

```
{
  "blockSize": [64, 64, 64],
  "compression": {
    "level": 3,
    "type": "zstd"
  },
  "dataType": "uint16",
  "dimensions": [256, 160, 413]
}
```
------
- [x] Added changelog entry (create a `$PR_NUMBER.md` file in
`unreleased_changes` or use `./tools/create-changelog-entry.py`)
- [x] Needs datastore update after deployment

---------

Co-authored-by: Florian M <fm3@users.noreply.github.com>

Author: mkitti

unreleased_changes/8703.md

@@ -0,0 +1,2 @@
+### Added
+- Added Zstandard support for N5

webknossos-datastore/app/com/scalableminds/webknossos/datastore/datareaders/n5/N5CompressorFactory.scala

@@ -8,7 +8,9 @@ import com.scalableminds.webknossos.datastore.datareaders.{
   GzipCompressor,
   NullCompressor,
   StringCompressionSetting,
-  ZlibCompressor
+  ZlibCompressor,
+  ZstdCompressor,
+  IntCompressionSetting,
 }
 
 object N5CompressorFactory {
@@ -28,6 +30,13 @@ object N5CompressorFactory {
         new ZlibCompressor(properties)
       case "gzip"  => new GzipCompressor(properties)
       case "blosc" => new BloscCompressor(properties)
+      case "zstd"  => {
+        val level = properties.get("level") match {
+          case Some(IntCompressionSetting(l)) => l
+          case _                              => throw new IllegalArgumentException("Zstd level must be int")
+        }
+        new ZstdCompressor(level, checksum = false)
+      }
       case _       => throw new IllegalArgumentException("Compressor id:'" + id + "' not supported.")
     }
 }