v4.0.0-alpha.1

Pre-release for Nextcloud 28

• fix links in Changelog by @Chartman123 in #1790
• Fix missing column in DataStructure.md by @Chartman123 in #1791
• Fix and update CI workflows by @susnux in #1792
• Min server 28 by @Chartman123 in #1796
• Build(deps): Bump @nextcloud/vue from 7.12.7 to 8.2.0 by @dependabot in #1794
• chore: Bump version to 4.0.0-alpha for main branch by @susnux in #1797
• chore(phpunit): Switch to phpunit workflow from organization by @susnux in #1795
• Make components compatible to nextcloud-vue 8 by @Chartman123 in #1696
• fix: Adjust composer scripts to work when only installing production dependencies by @susnux in #1798

Full Changelog: v3.4.0...v4.0.0-alpha.1