Fix <Datagrid> and <DataTable> bulk selection

[djhi]

Problem

When users select all rows matching their filters using the <SelectAllButton>, and then unselect rows using the <Datagrid> or <DataTable> header checkbox, all selected records are deselected instead of just the current page records.

Solution

Make sure only the currently displayed records are affected by the header checkbox.

How To Test

<Datagrid>

Story

1. Set the Rows per page option to 5
2. Select all records in the current page (either individually or using the header checkbox): You should have 5 selected records
3. Click the Select all bulk actions button: You should have 7 selected records
4. Click the header checkbox): You should have 2 selected records
5. Click the cross button in the bulk actions banner: You should have 0 selected records

<DataTable>

Story

1. Set the Rows per page option to 5
2. Select all records in the current page (either individually or using the header checkbox): You should have 5 selected records
3. Click the Select all bulk actions button: You should have 7 selected records
4. Click the header checkbox): You should have 2 selected records
5. Click the cross button in the bulk actions banner: You should have 0 selected records

Additional Checks

• The PR targets master for a bugfix or a documentation fix, 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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