* Add Mangamo
* Mangamo: Remove excess fields and use assertions
* Mangamo: improve Firestore queries
* Mangamo: synchronize auth
* Mangamo: fix serialization bug when no fields are returned from query
* Mangamo: exclude disabled manga from latest and improve chapter update query
* Mangamo: clean up DTO objects
* Mangamo: add custom 401 messaging, use emoji for payment indication
* Mangamo: make manga/chapter URLs relative
