fix: cache invalidation issues

[solracsf]

Problem

Context: nextcloud/server#57973 and nextcloud/server#49126

Files shared with teams were not syncing properly on desktop clients. When files were added, modified, or deleted in team-shared directories, the ETag was correctly updated in the database but clients received stale ETags from the distributed cache, preventing synchronization.

Root causes:

1. The clearCache() method in ShareWrapperService was broken - it used singleId as the cache key but actual keys follow the format singleId#nodeId#probeSum, causing cache invalidation to silently fail
2. No event listeners existed to detect file modifications and trigger cache invalidation - cache was only cleared when shares or memberships changed, never when files themselves were modified

Note

While testing, please enable debug mode to print debug messages.

[Ornanovitch]

/backport to stable33

[Ornanovitch]

/backport to stable32

[Ornanovitch]

/backport to stable31