Pass hints as environment to scripts (#440)

man/swaync.5.scd

@@ -728,5 +728,6 @@ SWAYNC_CATEGORY="SwayNC notification category"
 SWAYNC_REPLACES_ID="ID of notification to replace"
 SWAYNC_ID="SwayNC notification ID"
 SWAYNC_SUMMARY="Notification summary"
+SWAYNC_HINT_[NAME]="Value of the hint [NAME]"
 ```
 #END scripting

src/configModel/configModel.vala

@@ -247,6 +247,11 @@ namespace SwayNotificationCenter {
             spawn_env += "SWAYNC_REPLACES_ID=%s".printf (param.replaces_id.to_string ());
             spawn_env += "SWAYNC_TIME=%s".printf (param.time.to_string ());
             spawn_env += "SWAYNC_DESKTOP_ENTRY=%s".printf (param.desktop_entry ?? "");
+            foreach (string hint in param.hints.get_keys ()) {
+                spawn_env += "SWAYNC_HINT_%s=%s".printf (
+                    hint.up ().replace ("-", "_"),
+                    param.hints[hint].print (false));
+            }
 
             return yield Functions.execute_command (exec, spawn_env, out msg);
         }