settings.production: Allow extra azure configuration

Currently, the writing in the azure objstorage adds extra headers to the blobs. Which
prevents the correct reading of those blobs when checking the tarballs.

According to the documentation, this option opening should allow to configure more
appropriately.

Refs. swh/infra/sysadm-environment#5129

swh/deposit/settings/production.py

@@ -123,15 +123,27 @@ if cfg_azure:
                 f"Production: invalid configuration; missing {key} config entry."
             )
 
+    # Default options
+    options = dict(
+        azure_container=cfg_azure["container_name"],
+        connection_string=cfg_azure["connection_string"],
+    )
+
+    # Which may be enhanced with some extra options, lookup "object_parameters" in
+    # https://django-storages.readthedocs.io/en/latest/backends/azure.html
+    object_parameters = {}
+    for optional_config_key in ["content_type", "content_disposition"]:
+        if optional_config_key in cfg_azure:
+            object_parameters[optional_config_key] = cfg_azure[optional_config_key]
+
+    options.update(dict(object_parameters=object_parameters))
+
     STORAGES = {
         "staticfiles": {
             "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage"
         },
         "default": {
             "BACKEND": "storages.backends.azure_storage.AzureStorage",
-            "OPTIONS": {
-                "azure_container": cfg_azure["container_name"],
-                "connection_string": cfg_azure["connection_string"],
-            },
+            "OPTIONS": options,
         },
     }