Improve parameter's date widget components (a few of them) (#22802)

* add some basic unit tests

frontend/src/metabase/components/Calendar.stories.tsx

+import React from "react";
+import { ComponentStory } from "@storybook/react";
+import Calendar from "./Calendar";
+
+export default {
+  title: "Core/Calendar",
+  component: Calendar,
+};
+
+const Template: ComponentStory<typeof Calendar> = args => {
+  return <Calendar {...args} />;
+};
+
+export const Default = Template.bind({});
+Default.args = {};

frontend/src/metabase/components/DateAllOptionsWidget/index.ts

+export { default } from "./DateAllOptionsWidget";

frontend/src/metabase/parameters/components/widgets/DateRangeWidget.tsx → frontend/src/metabase/components/DateRangeWidget/DateRangeWidget.tsx

 import React from "react";
 
 import moment from "moment";
-import DateAllOptionsWidget from "./DateAllOptionsWidget";
+import DateAllOptionsWidget from "metabase/components/DateAllOptionsWidget";
 
 const SEPARATOR = "~"; // URL-safe
 

frontend/test/metabase/parameters/components/widgets/DateRangeWidget.unit.spec.js → frontend/src/metabase/components/DateRangeWidget/DateRangeWidget.unit.spec.js

 import React from "react";
 import { fireEvent, render, screen } from "@testing-library/react";
-import DateRangeWidget from "metabase/parameters/components/widgets/DateRangeWidget";
+import DateRangeWidget from "metabase/components/DateRangeWidget";
 
 describe("DateRangeWidget", () => {
   it("should allow selections spanning years", () => {

frontend/src/metabase/components/DateRangeWidget/index.ts

+export { default } from "./DateRangeWidget";

frontend/src/metabase/parameters/components/widgets/DateSingleWidget.tsx → frontend/src/metabase/components/DateSingleWidget/DateSingleWidget.tsx

 import React from "react";
 
 import moment from "moment";
-import DateAllOptionsWidget from "./DateAllOptionsWidget";
+import DateAllOptionsWidget from "metabase/components/DateAllOptionsWidget";
 
 interface DateSingleWidgetProps {
   setValue: (value: string | null) => void;

frontend/src/metabase/components/DateSingleWidget/DateSingleWidget.unit.spec.tsx

+import React from "react";
+import { render, screen } from "@testing-library/react";
+
+import DateSingleWidget from "./DateSingleWidget";
+
+describe("DateSingleWidget", () => {
+  it("should render correctly", () => {
+    render(
+      <DateSingleWidget
+        value={"2022-05-17"}
+        setValue={jest.fn()}
+        onClose={jest.fn()}
+      ></DateSingleWidget>,
+    );
+    screen.debug();
+    expect(screen.getByRole("textbox")).toHaveValue("05/17/2022");
+    expect(screen.getByText("May 2022")).toBeInTheDocument();
+  });
+});

frontend/src/metabase/components/DateSingleWidget/index.ts

+export { default } from "./DateSingleWidget";

frontend/src/metabase/parameters/components/ParameterValueWidget.jsx

@@ -5,12 +5,12 @@ import { t } from "ttag";
 
 import PopoverWithTrigger from "metabase/components/PopoverWithTrigger";
 import Icon from "metabase/components/Icon";
-import DateSingleWidget from "./widgets/DateSingleWidget";
-import DateRangeWidget from "./widgets/DateRangeWidget";
+import DateSingleWidget from "metabase/components/DateSingleWidget";
+import DateRangeWidget from "metabase/components/DateRangeWidget";
 import DateRelativeWidget from "metabase/components/DateRelativeWidget";
 import DateMonthYearWidget from "metabase/components/DateMonthYearWidget";
 import DateQuarterYearWidget from "metabase/components/DateQuarterYearWidget";
-import DateAllOptionsWidget from "./widgets/DateAllOptionsWidget";
+import DateAllOptionsWidget from "metabase/components/DateAllOptionsWidget";
 import TextWidget from "metabase/components/TextWidget";
 import ParameterFieldWidget from "./widgets/ParameterFieldWidget/ParameterFieldWidget";
 import Tooltip from "metabase/components/Tooltip";