Fix memory annotation deduplication (#2286)

* Add transform to deduplicate memory annotations
* Add annotation deduplication to Dedup stage
* ResolveAnnotationPaths and EliminateTargetPaths now invalidate the dedup annotations transform
* Verilog emitter now throws exception when memory annotations fail to dedup

Co-authored-by: Jack Koenig <koenig@sifive.com>