v4.18.0: Old Styles Use @layer, Improve Blog Settings, Fixes

What's Changed

• chore: do not clone bootstrap for tacc-search-bar by @wesleyboar in #879
• feat: WP-197 use @layer's / help migrate Frontera by @wesleyboar in #856
• refactor: define title block only in base by @wesleyboar in #883
• fix: blog install steps are outdated by @wesleyboar in #884
• chore: CMD-143 retire deprecated templates by @wesleyboar in #886
• deps: core-styles v2.35.1 by @wesleyboar in #887

Full Changelog: v4.17.1...v4.18.0