Shares information remains in webUI even after `sharee` is deleted

## Describe the bug
When a `sharee` is deleted after some resource is shared to him/her. The share information is still visible for that user in the `Shares` panel to the `Sharer`.

## Steps to reproduce
1. As an `admin` create a user `test`
2. Create file `hello.txt`
3. Share `hello.txt` to user `test`
4. Delete user `test`
5. Navigate to `Shares` panel for file `hello.txt`

## Expected behavior
There should not have been information shared to user `test`

## Actual behavior
Since the user is already deleted but its information is still in the shares panel which should not have been.


### Strange Behavior
After some times may be around a minute (do not know the exact time) or so the `sharee` information is deleted but the shares logo is still there in the UI as if the file is shared to some user but the shares list is empty.


## Setup
Please describe how you started the server and provide a list of relevant environment variables or configuration files.

```console
OCIS= Infinite Scale 5.1.0-prealpha+4d5490a601
WEB= ownCloud Web UI 8.0.0-rc.2
```

## Additional context
Add any other context about the problem here.