fix(SimpleFile): Catch exception and call checkFile() to sanitize broken appdata folder

[DerDreschner]

• Resolves: [Bug]: Preview Generation Fail - Local Storage #56510

Summary

During analyzing of #56510, I realized that broken appdata folders are not handled correctly since version 27 (this commit to be precise).

The issue here is that folders and their files can be listed in the oc_filecache database table, but not exist on filesystem anymore. If that is the case, our wrappers still work correctly as they always prefer the file cache... Until it comes to really read or write to the file system. And here our own putContent() and getContent() methods don't follow the same scheme as their put_file_contents() and get_file_contents() counterparts as we throw an exception instead of returning false.

This change isn't considered on all calls... I can only speak for the preview generation, as that's what I try to fix. The introduction of the oc_previews table fixed the issue there, which means only Nextcloud 32 and older are affected by this bug. But a quick look through the code tells me that there are still a lot more cases that expect false in case of an error, while others already catch an NotFoundException (that's only being thrown when there's no hit against the file cache or method calls like checkPermission() fail... Ohh lord...).

Anyway... With this change, the preview generation will restore the correct appdata structure and starts to generate previews instead of being broken until someone runs occ preview:cleanup manually.

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)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[DerDreschner]

/backport to stable33

[DerDreschner]

/backport to stable32

[DerDreschner]

But a quick look through the code tells me that there are still a lot more cases that expect false in case of an error, while others already catch an NotFoundException (that's only being thrown when there's no hit against the file cache or method calls like checkPermission() fail... Ohh lord...).

Please have a look into the CI pipeline and the failed psalm run. That uncovers the surface of the mess. 😓 Help anyone?