IcPaginationBar - Cannot use 'All' option along with custom ItemsPerPage

### Summary of the bug
When using IcPaginationBar along with a custom value for the 'itemsPerPageOptions' prop, the 'All' option does not appear in the 'Items per page' select, regardless of the value of the 'hideAllFromItemsPerPage' prop.

### 🪜 How to reproduce
Tell us the steps to reproduce the problem:
1. Go to page: https://design.sis.gov.uk/components/navigation/pagination-bar/code/#variants
2. Click on: The 'Items per page' select on the 'Show items per page control' example
3. See that there is no 'All' option

### 📸 Screenshots or code

There is no 'All' option visible despite the 'hideAllFromItemsPerPage' prop being omitted.

### 🧐 Expected behaviour
The 'All' option should be visible in the 'Items per page' select

### 📝 Acceptance Criteria
Allow the 'All' option to be selectable in the 'Items per page' select
Add a cypress test for this case, and set all the skipped tests to be run.

Start at the IcPaginationBar implementation and trace how itemsPerPageOptions and hideAllFromItemsPerPage determine the select options. Add a Cypress test covering a custom itemsPerPageOptions value with the All option visible and selectable, then enable the skipped tests and run the relevant Cypress coverage.

Written by the indexing model from the issue text.