feat: form for editing ws schedule (#1634)

* feat: ui for editing ws schedule

Summary:

This presents a form component and storybook. The UI will be a routed
page and added into the dashboard in a separate PR. It is likely a
XService will be used at the page level to supply errors and actions to
this form.

Impact of Change:

Further progress on #1455

Squashed Commits:

* refactor: add className prop to Stack

combine classes with internal classes and an optional external className
to better control the Stack.

* fix: getFormHelpers helperText

the helperText logic was incorrect, the helperText would only show if not touched.

site/src/util/formUtils.ts

@@ -28,7 +28,7 @@ export const getFormHelpers =
       ...form.getFieldProps(name),
       id: name,
       error: touched && Boolean(error),
-      helperText: touched ? error : helperText,
+      helperText: touched ? error || helperText : helperText,
     }
   }