Exposure of maps and infos in module enhance

**Is your feature request related to a problem? Please describe.**
Sometimes I have to do some tricks on the generated types(models, resolvers, inputtypes, etc), but I cannot retrive a list of them in the generated SDK. I noticed that all the data I need are in module `enhance`, but they are not exported.

**Describe the solution you'd like**
Just simply export `*Map` and `*info` in module `enhance`.

**Describe alternatives you've considered**
N/A

**Additional context**
Do some type manipulation may dig out some data, but I have no idea how to get more:

```ts
declare type model_names_type = any extends ModelConfig ? K : never;
const model_names = foo // ???
const model_fields = ... // ???
```

Start by inspecting the generated SDK's enhance module, where the *Map and *info data is currently available but not exported. Identify the relevant generated type, resolver, and input-type metadata, then expose those entries and verify that consumers can access them from enhance.

Written by the indexing model from the issue text.