docs: update progress field
docs: update progress field

Avoid naming the progress free text field 'message' as it conflicts with the
message itself.

ylatuya/gstreamer,lovebug356/gstreamer,centricular/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,shelsonjava/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,Lachann/gstreamer,StreamUtils/gstreamer,magcius/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,ahmedammar/platform_external_gst_gstreamer,lubosz/gstreamer,surround-io/gstreamer,Distrotech/gstreamer,cfoch/gstreamer,cablelabs/gstreamer,drothlis/gstreamer,collects/gstreamer,cablelabs/gstreamer,justinjoy/gstreamer,mparis/gstreamer,Distrotech/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,shelsonjava/gstreamer,mparis/gstreamer,jpakkane/gstreamer,ahmedammar/platform_external_gst_gstreamer,cfoch/gstreamer,surround-io/gstreamer,shelsonjava/gstreamer,drothlis/gstreamer,jpakkane/gstreamer,StreamUtils/gstreamer,cfoch/gstreamer,krichter722/gstreamer,ensonic/gstreamer,centricular/gstreamer,krieger-od/gstreamer,krieger-od/gstreamer,Distrotech/gstreamer,ahmedammar/platform_external_gst_gstreamer,Lachann/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,ensonic/gstreamer,centricular/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,ensonic/gstreamer,magcius/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,mparis/gstreamer,ylatuya/gstreamer,ensonic/gstreamer,collects/gstreamer,jpakkane/gstreamer,ahmedammar/platform_external_gst_gstreamer,Lachann/gstreamer,mparis/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,cablelabs/gstreamer,drothlis/gstreamer,jpxiong/gstreamer,ylatuya/gstreamer,StreamUtils/gstreamer,collects/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,centricular/gstreamer,ylatuya/gstreamer,Distrotech/gstreamer,jpxiong/gstreamer,lubosz/gstreamer,justinjoy/gstreamer,magcius/gstreamer,lovebug356/gstreamer,justinjoy/gstreamer,magcius/gstreamer,ylatuya/gstreamer,surround-io/gstreamer,krichter722/gstreamer,ensonic/gstreamer,lubosz/gstreamer,lubosz/gstreamer,collects/gstreamer,Lachann/gstreamer,krieger-od/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,ahmedammar/platform_external_gst_gstreamer,lovebug356/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,lovebug356/gstreamer,collects/gstreamer,Lachann/gstreamer,magcius/gstreamer,drothlis/gstreamer,lovebug356/gstreamer,drothlis/gstreamer