Make "Extended Search" more visible

[andre-hohmann]

Problem

The "extended search" is only offered in the process list and the task list and thus usable only after some klicks.
In addition, the "extended search" belongs from my point of view to the "simple search", which is always accessible.

Solution

The "extended search"-button should be placed between the "simple search"-box and the breadcrumbs. Maybe, it can be reduced with a hover-effect for the description. As it is applied for the "action"-symbols in the process list.
This should be considered, when #3512 is realized.