Add ability to delete context values from sidebar

packages/node_modules/@node-red/editor-api/lib/admin/context.js

@@ -37,5 +37,20 @@ module.exports = {
         }).catch(function(err) {
             apiUtils.rejectHandler(req,res,err);
         })
+    },
+
+    delete: function(req,res) {
+        var opts = {
+            user: req.user,
+            scope: req.params.scope,
+            id: req.params.id,
+            key: req.params[0],
+            store: req.query['store']
+        }
+        runtimeAPI.context.delete(opts).then(function(result) {
+            res.status(204).end();
+        }).catch(function(err) {
+            apiUtils.rejectHandler(req,res,err);
+        })
     }
 }