Update TodosApi app to use Dapper AOT

We should update 

https://github.com/aspnet/Benchmarks/blob/89376026c9f8c1012a0230a083dec0198f03bbad/src/BenchmarksApps/TodosApi/TodosApi.csproj#L18

To use https://github.com/DapperLib/DapperAOT/ instead. DapperAOT is more widely used. It would be better to get measurements using DapperAOT instead of Nanorm.

cc @DamianEdwards @mgravell 