feat(acr): aligning formatDate utility with ADR012 using Luxon

[its-mitesh-kumar]

Description

This pull request refactors the formatDate utility to use luxon instead of date-fns. This work is part of the larger effort to remove dependencies on the @janus-idp/shared-react package.

This change aligns the utility with ADR012: Adopt Luxon as a standardized date and time library, which aims to standardize date/time handling across the codebase for better consistency and maintainability.

The new implementation maintains the existing function signature and behavior:

• It correctly handles string, number (Unix timestamp), and Date object inputs.
• It continues to return 'N/A' for null, undefined, or invalid date inputs.
• The output format string has been updated to the luxon equivalent to ensure consistent presentation.

Fixes

Fixing https://issues.redhat.com/browse/RHIDP-7403

UI before changes

UI after changes

[backstage-goalie]

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
@backstage-community/plugin-acr	workspaces/acr/plugins/acr	patch	v1.14.1

[debsmita1]

• please remove the shared-react dependency from the package.json if it is not used anymore in the acr plugin and re-run yarn install to update the yarn.lock
• add tests for the new util