Fixed XIF Control Signals for Sticky Accept/Reject

Created by: Aidan-McNay

A quick fix I noticed when using the core; a lot of my issue responses weren't able to write back due to the lack of tracking XIF control signals when the pipeline was stalling (a.k.a. "sticky accepts"). This fix keeps track of these signals on sticky accepts to ensure that they are correctly forwarded. @Silabs-ArjanB @silabs-oysteink Let me know what you think!

(I tried following the link in the Contributing guidelines to OpenHW Work Flow document, but it seemed broken - let me know if there's anything I need to fix!)