4 people 88a03a6133 Link mentioned user in markdown only if they are visible to viewer (#21554) ...

We need to make sure a user can't confirm the existence of a user with
private visibility

* Follow up on #21533 

### Before
#### User

![image](https://user-images.githubusercontent.com/20454870/197357580-340911d7-1659-4fc9-a9f6-7ed6bc3476b4.png)

#### Admin

![image](https://user-images.githubusercontent.com/20454870/197357676-a8f0ae63-8f80-4221-a9b5-b6311552910a.png)

### After
#### User

![image](https://user-images.githubusercontent.com/20454870/197357536-05616edb-7821-469d-8e51-6f8cb84c1362.png)

#### Admin

![image](https://user-images.githubusercontent.com/20454870/197357703-071fe984-de79-43aa-a77c-a85b046292a4.png)

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

2022-10-23 17:13:52 +08:00

..

main_test.go

…

processorhelper_test.go

…

processorhelper.go

…