Debugger: Fix tooltip expansion behavior

Task-number: QTCREATORBUG-11404
Change-Id: I7e08cd6b8216ff7dd0069c2a8718f6bb619ede07
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Debugger: Move string size settings to L&E page

They belong there conceptionally, and there's more space.

Change-Id: I5167ed3713266af866aebff00eec848f74b4c2b9
Reviewed-by: Eike Ziller <eike.ziller@digia.com>