Investigate augmenting model with EF code-first model metadata

# Problem
Many EF features can only be configured via OnModelCreating, which Coalesce cannot be aware of.

# Solution
If we could figure out how to access this data at generation time (getting it at runtime is easy), that would open the doors to a whole new world of features. Investigate how this works in EF tooling like migrations or compiled models.

Also see https://github.com/dotnet/efcore/issues/11659