Breaking: #62595 - Remove SU change-to mode 

See forge#62595

Description 

The permanent user switch has been removed from backend user list for a better UX.

Impact 

The parameter "emulate" in the view helper "SwitchUser" is dropped. Using the argument causes an error "Argument "emulate" was not registered".

Affected installations 

Any installation using an extension that uses the view helper "SwitchUser" with "emulate" argument.

Migration 

Drop the "emulate" argument in the view helper call.