Create new activity without prefilled content

A user did not like that we prefill the activity create form. The user creates all activities in one go (and chronologically) and was annoyed that the values of the inputs need to be cleared, before another value can be entered. Maybe we need/could use this model also for other dialogs.

### Possible solutions
#### Additional Button

Button group with a additional button to copy the settings and open the dialog again

#### Copy from last created activity if nothing else was copied

Make the paste button multifunctional

#### Use a keyboard modifier

If you press Ctrl or Cmd then the button text and action changes.