Resident Evil Survivor (PS1) Is RE Survivor Cannon?

I have never played this game

It indeed fits the canonical criteria

To elaborate, it takes place a month before Resident Evil: Code: Veronica

Ye it is.

I believe Survivor is cannon because like you said it was mentioned in RE0. I also believe that the Outbreak games were canon and that they showed how other civilians managed to escape Raccoon City besides just the main characters in Resident Evil 2 and 3.