Cannot edit user with @ in name

[marius-dr]

Kibana version: 7.10.0

Describe the bug:
If an user has @ in their name, the edit URL for it gets encoded and changed to %40 so Kibana throws an error "user doesn't exist".
Workaround is to copy the URL and replace %40 with @ manually.
Steps to reproduce:

1. Create an user with the name test@test
2. Try to edit the user.

Expected behavior:
We should handle @ as part of the username as well. Not allowing it is not a solutions since we have usernames that get mapped from emails.

Any additional context:

It was most likely introduced by: #81562

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)

[legrego]

There is a bug in react-router/history that is the root cause of this. Details are in #82440

[legrego]

We are expecting this fix to land in the 7.10.1 release