2024-03.2 Add sentry browser sdk and update banners

What's Changed

• DWPF-1472 Removal of beta banner and new background colour for site alert banner by @nicopicchio in #553
• Makefile standardisation by @nicopicchio in #550
• DWPF-1466 Add sentry browser sdk for performance monitoring by @SamDudley in #551
• Makefile update by @nicopicchio in #554

Full Changelog: 2024-03.1...2024-03.2