feat: adjust preview app loading

[AlexAndBear]

Description

• Refactored component to <script setup>
• Merged filteredFiles and cachedFiles props into a single prop mediaFiles
• Cancel ongoing image loading when quickly skipping to another image before loading completes
• Decoupled photo roll previews

Related Issue

• Fixes Preview app: Reasonable preloading #1772

How Has This Been Tested?

• test environment:
• test case 1:
• test case 2:
• ...

Types of changes

• Bugfix
• Enhancement (a change that doesn't break existing code or deployments)
• Breaking change (a modification that affects current functionality)
• Technical debt (addressing code that needs refactoring or improvements)
• Tests (adding or improving tests)
• Documentation (updates or additions to documentation)
• Maintenance (like dependency updates or tooling adjustments)

[AlexAndBear]

We can’t rely on requesting a preview at this point. When files are opened from the tiles view, all images in the photo roll are already loaded. If, for example, an MP4 file is opened, it doesn’t provide a preview flag via PROPFIND, so we don’t make any preview-endpoint requests here.

[kulmann]

Nice job! 😍

I found a tiny edge case for the photo roll preview: when you delete and file and then restore it via the button in the notification, the file re-appears in the photo roll and is clickable and everything, but the thumbnail doesn't load. Maybe something for a followup though 😅

[kulmann]

.... forgot in my review to switch from Comment to Approve. 🙈 sorry.

[AlexAndBear]

Thank you, I will do the enhancements in the following pr which is about the photo roll improvements