Added MimeTypeDatabase for UFP extension

CURA-5323

plugins/UFPWriter/__init__.py

@@ -11,6 +11,16 @@ except ImportError:
 
 from UM.i18n import i18nCatalog #To translate the file format description.
 from UM.Mesh.MeshWriter import MeshWriter #For the binary mode flag.
+from UM.MimeTypeDatabase import MimeTypeDatabase, MimeType
+
+
+MimeTypeDatabase.addMimeType(
+    MimeType(
+        name = "application/x-cura-stl-file",
+        comment = "Cura UFP File",
+        suffixes = ["ufp"]
+    )
+)
 
 i18n_catalog = i18nCatalog("cura")