Sort configs & splits alphabetically

Sorts dataset configs and splits alphabetically (as done with tasks and datasets) to make finding desired configs/splits more straightforward.

app.py

@@ -190,12 +190,12 @@ else:
 dataset_df = dataset_df.dropna(axis="columns", how="all")
 
 if len(dataset_df) > 0:
-    config_set = set(dataset_df["config"])
+    selectable_configs = list(set(dataset_df["config"]))
+    selectable_configs.sort(key=lambda name: name.lower())
+
     if "-unspecified-" in config_set:
-        config_set.discard("-unspecified-")
-        selectable_configs = ["-unspecified-"] + list(config_set)
-    else:
-        selectable_configs = list(config_set)
+        selectable_configs.discard("-unspecified-")
+        selectable_configs = ["-unspecified-"] + selectable_configs
 
     if dataset != "-any-":
         config = st.sidebar.selectbox(
@@ -206,12 +206,13 @@ if len(dataset_df) > 0:
         )
         dataset_df = dataset_df[dataset_df.config == config]
 
-        split_set = set(dataset_df["split"])
+        selectable_splits = list(set(dataset_df["split"]))
+        selectable_splits.sort(key=lambda name: name.lower())
+
         if "-unspecified-" in split_set:
-            split_set.discard("-unspecified-")
-            selectable_splits = ["-unspecified-"] + list(split_set)
-        else:
-            selectable_splits = list(split_set)
+            selectable_splits.discard("-unspecified-")
+            selectable_splits = ["-unspecified-"] + selectable_splits
+
         split = st.sidebar.selectbox(
             "Split",
             selectable_splits,