Refact: Renaming bf.streams, oa.streams in bf.dsp, oa.dsp

[detlefarend]

Motivation This change in the terminology sharpens and clarifies the package structure of MLPro. This also avoids odd combinations like

• mlpro.bf.streams.streams
• mlpro.oa.streams.streams

Benefit ...

Are the proposed changes backward compatible?

• [ ] Yes
• [ ] No

Related development objects

• [ ] bf.streams
• [ ] oa.streams
• [ ] related howtos
• [ ] bf.control
• [ ] oa.control
• [ ] bf.systems
• [ ] oa.systems