Default client

[solth]

Is your feature request related to a problem? Please describe.
When a user has multiple clients assigned to him but mainly uses one of those clients most of the time, it can quickly become cumbersome to always select the same client when logging into the system.

Describe the solution you'd like
It should be possible to configure a default client that is automatically selected when a user logs into the system and has multiple clients. Configuring a default client should be optional, though, and the system should work as it currently does when no default client is configured.

Describe alternatives you've considered
It may be worth considering a slight variation of the solution proposed above where the default client is automatically selected in the "Select client" popup dialog upon login, but the user still has to confirm the selection. He might thus still select a different client when required.

Additional context
Since it is possible to change the client using the user menu in the upper right corner of the screen at any time after login I would prefer the first approach, where an optional default client is not only pre-selected, but the selection is actually committed so that the user can skip the whole client selection entirely during login if he opts to use the option.