Spyglass has three different files that define exceptions. This change
merges all of those definitions into a single file for simplicity.
Before this change can be merged, spyglass-plugin-xls needs to move the
exceptions needed for its functions.
Related Change: https://review.opendev.org/#/c/667243/
Depends-On: I81c5ca2d9083aece3641bc8b5405dfd44baec810
Change-Id: Ibf34771653247850903e529beb17dbd60ba35fbf
43b6d78d00