[FEATURE] XLSX reports

[gulderov]

I would like to propose the addition of XLSX report generation.
This feature aims to mirror the functionality of the current CSV reports. It will enable users to generate XLSX reports directly from Discover and Reports Dashboards

Implementation details:

1. Download button should be added to popover:

2. The file format selector needs to be updated with xlsx format option

3. Reports Dashboard should allow to download xlsx format

4. Add xlsx format to opensearch-project/reporting