refactor(comments): migrate to Vue 3

[edward-ly]

Summary

• Part of 📦 ❗️Vue 3 Migration - NC33 Roadmap #55428

TODO

Currently, npm run dev/build fails with this error. I suspect it has something to do with the CommentInstance class requiring a Vue 2 options object which I'm not yet sure how to cleanly migrate to Vue 3.

error during build:
[vite:css-post] object null is not iterable (cannot read property Symbol(Symbol.iterator))
    at assetFileNames (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/.vite-temp/vite.config.ts.timestamp-1771208851828-a019a06c76d568.mjs:95:33)
    at Object.assetFileNames (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/@nextcloud/vite-config/dist/plugins/CSSEntryPoints.js:28:65)
    at generateAssetFileName (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:21662:25)
    at FileEmitter.finalizeAdditionalAsset (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:21955:28)
    at FileEmitter.emitAssetWithReferenceId (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:21899:18)
    at FileEmitter.emitAsset (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:21884:18)
    at FileEmitter.emitFile (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:21745:25)
    at Object.renderChunk (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/vite/dist/node/chunks/config.js:29806:32)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async transformChunk (file:///home/edward/projects/nextcloud/nextcloud-docker-dev/workspace/server/node_modules/rollup/dist/es/shared/node-entry.js:20311:16)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)