Migrate an EF Core Cosmos app after the generated id escaping change in EF Core 11
EF Core 11 stops escaping '/', '\', '?' and '#' in generated Cosmos DB id values, so documents written by EF Core 8-10 stop resolving by key. How to find out if you are affected, when to set the EscapeIllegalCosmosIdCharacters switch, and how to rewrite the ids safely with a transactional batch.