Map: Missing location markers in Siofra River

Landmarks:
- [ ] Hallowhorn Grounds (Ancestor Spirit)
- [ ] Night's Sacred Grounds
- [ ] Nokron, Eternal City
- [ ] Siofra Aqueduct
- [ ] Hallowhorn Grounds (Regal Ancestor Spirit)

Bosses:
- [ ] Ancestor Spirit
- [ ] Dragonkin Soldier
- [ ] Mimic Tear
- [ ] Dual Gargoyles