fix(server): more asset upload validation and docs (#1720)

* fix(server): more asset upload validation and docs

* remove unused DTO

* changed Object.keys() to Object.values()

* apply patch to openapi generator for web

* revert CreateAssetDto assetType enum

* resolve merge conflict

* Revert "resolve merge conflict"

This reverts commit 0e0080518759a05d029f2f7a761537c58cb586d0.

server/openapi-generator/patch/api_client.dart.patch

@@ -18,4 +18,4 @@
        ? json
 -      : _deserialize(jsonDecode(json), targetType, growable: growable);
 +      : _deserialize(await compute((String j) => jsonDecode(j), json), targetType, growable: growable);
-   }
+   }