List of speakers (menu): new filter for speech type

[MSoeb]

Description: In the current list of speakers menu it is possible to export speech data with speech type, but it is not possible to filter by this value.

What should happen:
A new filter should be integrated, which provides the possbility to search by speech type.

Filter name: Speech Type
Filter values: All types of speecher, which are exported. Examples are Interposed questions, point of order, and so on.