Fix blockly datetime picker

marlowe-playground-client/src/Blockly/Blockly.ts

@@ -0,0 +1,23 @@
+import { BlockBase, BlockCreate, BlockChange } from "blockly/core/events/events";
+
+export function createBlocklyInstance_ () {
+  return import("blockly");
+};
+
+export type Blockly = Awaited<ReturnType<typeof createBlocklyInstance_>>;
+export type Workspace = InstanceType<Blockly["Workspace"]>
+export type WorkspaceSvg = InstanceType<Blockly["WorkspaceSvg"]>
+export type Block = InstanceType<Blockly["Block"]>
+
+export type TZInfo = {tzOffset: number, offsetString: string}
+
+export function isBlockEvent (event: unknown): event is BlockBase {
+  return event.hasOwnProperty("blockId");
+}
+
+export function isBlockCreateEvent (event: unknown): event is BlockCreate {
+  return event.hasOwnProperty("type") && event["type"] == "create";
+}
+export function isBlockChangeEvent (event: unknown): event is BlockChange {
+  return event.hasOwnProperty("type") && event["type"] == "change";
+}