Feat/bulk delete UI

[psanghvi17]

PR Checklist

• Linting Test is passing
• Code is well documented
• If applicable, a PR in the epinio/docs repository has been opened

Summary

Adds UI bulk delete support for Epinio resources by introducing a reusable confirmation modal and table row selection, then wiring bulk delete flows into the relevant list views. A follow-up fix also aligns the new flow with existing delete safeguards for configurations and application image deletion.

Occurred changes and/or fixed issues

• Added a reusable BulkDeleteModal for confirmation flows.
• Extended the shared DataTable with:
  • row selection
  • select-all support
  • controlled selected row keys
  • row-level selectability
• Added bulk-delete i18n strings for button labels, titles, descriptions, and deleting states.
• Added bulk delete UI flows for:
  • Applications
  • Services
  • Configurations
  • Namespaces
• Added optional "Also delete image from registry" support for bulk application deletion.
• Fixed bulk configuration deletion so non-deletable/service-related configurations cannot be selected.
• Fixed bulk application deletion so the temporary deleteImage flag does not leak into later delete attempts.

Technical notes summary

• No backend changes were required for this work; the UI reuses the existing bulk delete support already exposed through the Epinio models/endpoints.
• Application bulk delete works across namespace-grouped tables by merging selection from each namespace section into one bulk action.
• DataTable now supports rowSelectable, allowing protected rows to remain visible while preventing them from being selected.
• The safeguard follow-up keeps bulk delete behavior aligned with existing single-delete rules, especially for configurations and app image deletion behavior.
• Namespace bulk delete was included as an additional UI capability/collateral improvement.

Areas or cases that should be tested

• Applications: select one or more apps in a namespace, open bulk delete, confirm deletion, and verify list refresh.
• Applications: select apps across multiple namespace sections, confirm deletion, and verify all selected apps are removed correctly.
• Applications: enable and disable "Also delete image from registry" and verify the choice only applies to the current delete action.
• Services: bulk delete one or more services and verify the list refreshes correctly after success/failure.
• Configurations: bulk delete normal configurations and verify service-related/protected configurations are shown but cannot be selected.
• Namespaces: bulk delete multiple namespaces and verify the list refreshes correctly afterward.
• RBAC: verify bulk delete buttons and selection checkboxes only appear for users with the required permissions.
• Shared table behavior: verify checkbox state, select-all behavior, pagination, search, and modal cancel/close behavior.

Areas which could experience regressions

• Any page using the shared DataTable, especially around selection, pagination, search, sorting, and action-column layout.
• Existing single-delete flows for applications, services, configurations, and namespaces.
• Application delete flows that pass the deleteImage option.
• Configuration delete permissions and service-related configuration handling.
• Namespace-grouped application list behavior and cross-table selection state.