Fix <DateInput> and <DateTimeInput> do not react to form changes

[djhi]

Problem

<DateInput> and <DateTimeInput> do not react to form changes. For instance if you use react-hook-form hooks to set the value.

Fixes #10320

Solution

Make sure we update the internal value when it changes from outside.

How To Test

There are two new stories and matching tests:

• DateTimeInput: https://react-admin-storybook-c6qu3ea65-marmelab.vercel.app/?path=%2Fstory%2Fra-ui-materialui-input-dateinput--external-changes
• DateInput: http://localhost:9010/?path=/story/ra-ui-materialui-input-dateinput--external-changes

Additional Checks

• The PR targets master for a bugfix, or next for a feature
• The PR includes unit tests (if not possible, describe why)
• The PR includes one or several stories (if not possible, describe why)
  - [ ] The documentation is up to date

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