design: rename passthrough negotiation
design: rename passthrough negotiation

Rename passthrough negotiation to transform negotiation to avoid
confusion with passthrough operation.

collects/gstreamer,surround-io/gstreamer,krichter722/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,lovebug356/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,collects/gstreamer,cablelabs/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,cfoch/gstreamer,lubosz/gstreamer,krieger-od/gstreamer,Lachann/gstreamer,collects/gstreamer,cfoch/gstreamer,centricular/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,cfoch/gstreamer,ensonic/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,centricular/gstreamer,centricular/gstreamer,lovebug356/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,justinjoy/gstreamer,ensonic/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,justinjoy/gstreamer,lubosz/gstreamer,lovebug356/gstreamer,justinjoy/gstreamer,centricular/gstreamer,cablelabs/gstreamer,cfoch/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,mparis/gstreamer,mparis/gstreamer,mparis/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,Lachann/gstreamer,lubosz/gstreamer,mparis/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,ensonic/gstreamer,Lachann/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,krieger-od/gstreamer,collects/gstreamer,shelsonjava/gstreamer,surround-io/gstreamer,surround-io/gstreamer,Lachann/gstreamer,StreamUtils/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,mparis/gstreamer,collects/gstreamer,jpxiong/gstreamer