Deep props make Query send request on every update

[PPierzc]

What you were expecting:
The Query component should send a request on update only when the props have changed.

What happened instead:
Sends request on every update

Steps to reproduce:
Create a deep payload object for the Query component.

Related code:

const payload = {
      id: record.id,
      target: 'author',
      sort: {
        order: 'DESC',
        field: 'createdAt'
      },
      pagination: {
        page: 1,
        perPage: 1
      }
}

return (
      <Query
        type='GET_MANY_REFERENCE'
        resource={constants.resources.posts}
        payload={payload}
      >
        {({ data, loading, error }) => {
          return <></>
      </Query>
)

Other information:
A solution could be to change shallowEqual in the Query's componentDidUpdate to deepEqual.

Environment

• React-admin version: 2.9.0
• Last version that did not exhibit the issue (if applicable): -
• React version: 16.6.3
• Browser: Google Chrome 73
• Stack trace (in case of a JS error): -

[Kmaschta]

Related to #3146

The Query component use a shallowEqual, is it on purpose @fzaninotto ?

react-admin/packages/ra-core/src/util/Query.tsx

Lines 110 to 111 in e0bdf6d

	!shallowEqual(prevProps.payload, this.props.payload) ||
	!shallowEqual(prevProps.options, this.props.options)